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DEPARTMENT OF THE INTERIOR 
UNITED STATES GEOLOGICAL SURVEY 

GEORGE OTIS SMITH, Dieectob 

Water-supply Paper 319 



&EOLOGY AND GROUND WATERS 
OF FLORIDA 



BY 

GEORGE CHARLTON MATSON 

AND 

SAMLICL SANFORD 



Prepared in cooperation between the United States Geological Soryey and the Florida 
Geological Survey, under the. direction of Thomas Wayland Vaughan 




tVASHINGTON 

aOVERNMENT PRINTING OFFICE 

1913 



'^onofifraph 



DEPAKTMENT OF THE INTERIOR 
UNITED STATES GEOLOGICAL SURVEY 

GEORGE OTIS SMITH, Dieectob 



Water- Stipply Paper 319 



GlEOLOCT AXD GROU^^D WATERS 
OF FLORIDA 

BY ^ 

GEORGE CHARLTOX ]^IATSON 

AND 

SA]^1UEL SAXFORD 



Prepared in cooperation between the United States Geological Surrey and tiie Florida 
Geological Survey, under the direction of Thomas Wayland Yaughan 




WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1913 



Of 






oftt> 



n, OF D. 

jAi^ ID ^914 



^ 



X 



p. 

*^ CONTENTS. 



Page. 

Introduction 17 

Part I.— Geography 21 

Northern and central Florida, by G. C. Matson 21 

Nature of country. 21 

ReUef 21 

Drainage 23 

Rivers -. 23 

Lakes and swamps 24 

Topographic provinces 25 

Characteristic features 25 

Upland or lake region 25 

Underground drainage. 25 

Caverns 26 

Sink holes 26 

Natural bridges 28 

Springs 29 

Erosional features 80 

Lakes 30 

Sand dunes j 30 

Lowland 30 

Streams and ponds 31 

Ridges 31 

Sand dunes , 31 

Terraces 31 

General features 31 

Newberry terrace 32 

Tsala Apopka terrace 33 

Pensacola terrace 34 

The coast 35 

Coral reefs 35 

Submerged continental border 35 

Bars 37 

Sounds 37 

Inlets 38 

Tidal runways 38 

Capes : 38 

Soils • 39 

Origin and character 39 

Soil types 40 

Southern Florida, by Samuel Sanford 42 

Location and area 42 

General features 42 

1 



2 CONTENTS. 

Part I. — Geography — Continued. 

Southern Florida, by Samuel Sanford — Continued. Page. 

The mainland 45 

Subdivisions 45 

Pinelands 45 

Area and distribution 45 

Dunes 46 

Character 46 

Distribution 47 

RolUng sand plains 49 

Flatlands... 50 

E-ock ridges 51 

Swamps 52 

Controlling conditions. 52 

Everglades 53 

Extent 53 

Elevation and drainage 54 

Bedrock 55 

Origin 57 

Cypress swamps •. 58 

Coastal swamps 58 

The keys 59 

General character , 59 

The Florida reef 61 

The shore line 62 

Topography 62 

Ocean currents 63 

Part II. ^Geology 65 

Northern and central Florida, by G. C. Matson 65 

Geologic record 65 

General succession of formations 65 

Tertiary system 71 

Oligocene series 71 

Subdivisions 71 

Vicksburg group 71 

Nomenclature 71 

Marianna and ' ' Peninsular " limestones 73 

Stratigraphic position 73 

Lithologic character 73 

Thickness 73 

Physiographic expression 74 

Paleontologic character 74 

Structure 74 

Areal distribution 75 

Ocala limestone 79 

Nomenclature 79 

Stratigraphic position 80 

Lithologic character 81 

Thickness ' 81 

PhysiogTaphic expression 81 

Paleontologic character 82 

Structure 82 

Areal distribution 82 

"Miliolite limestone" 85 



^ 



CONTENTS. 3 

Part II. — Geology — Continued. 

Northern and central Florida, by G. C. Matson — Continued. 
Tertiary system — Continued. 

Oligocene series — Continued. page. 

Apalachicola group 85 

Nomenclature 85 

Hawthorn formation 87 

General character 87 

Stratigraphic position 88 

Lithologic character 89 

Thickness 89 

Physiographic expression '. . 89 

Paleontologic character 89 

Structure 90 

Areal distribution. 90 

Chattahoochee formation 93 

Nomenclature 93 

Stratigraphic position 93 

Lithologic character 94 

Thickness 95 

Physiographic expression 95 

Paleontologic character 95 

Structure 96 

Areal distribution 96 

Tampa formation 102 

Character and nomenclature 102 

Stratigraphic position 103 

Lithologic character 103 

Thickness : 104 

Physiographic expression 104 

Paleontologic character 104 

Structure , 105 

Areal distribution 105 

Alum ^luff formation 108 

Members 108 

Stratigraphic position 108 

Lithologic character 109 

Thickness 110 

Physiographic expression Ill 

Paleontologic character Ill 

Structure Ill 

Areal distribution Ill 

Chipola marl member 117 

Oak Grove sand member 119 

Shoal River marl member 120 

Miocene series 121 

Nomenclature and subdivisions 121 

Jacksonville formation 123 

Stratigraphic position 123 

Lithologic character 123 

Thickness 125 

Physiographic expression 125 

Paleontologic character 125 

Structure 126 

Areal distribution 126 



4 . CONTENTS. 

Part II. — Geology — Continued. 

Northern and central Florida, by G. C. Matson — Continued. 
Tertiary system — Continued. 

Miocene series — Continued. Page. 

Choctawhatchee marl 127 

Stratigraphic position 127 

Lithologic character 128 

Thickness 129 

Physiographic expression 129 

Paleontologic character 129 

Structure 130 

Areal distribution 130 

Pliocene series 133 

Caloosahatchee marl 134 

Nomenclature 134 

Stratigraphic position 134 

Lithologic character 135 

Thickness 135 

Physiographic expression 135 

Paleontologic character 135 

Structure 135 

Areal distribution 136 

Nashua marl 138 

Discrimination 138 

Stratigraphic position 139 

Lithologic character 139 

Thickness 139 

Physiographic expression 139 

Paleontologic character 139 

Structure 140 

Areal distribution 140 

Alachua clay 141 

Deposition 141 

Stratigraphic position 142 

Lithologic character 142 

Thickness 142 

Physiographic expression 142 

Paleontologic character 142 

Structure 143 

Areal distribution 143 

Bone Valley gravel 144 

Nomenclature 144 

Stratigraphic position 145 

Lithologic character 145 

Thickness 145 

Physiographic expression 146 

Paleontologic character 146 

Structure 146 

Areal distribution 146 

Pliocene (?) series 146 

Lafayette (?) formation 146 

Correlation 146 

Stratigraphic position 147 



^ 



CONTENTS. 5 

Part II. — Geology — Continued. 

Northern and central Florida, by G. C. Matson — Continued. 
Tertiary system — Continued. 

Pliocene (?) series — Continued. 

Lafayette (?) formation — Continued. Page. 

Lithologic character 147 " 

Thickness 148 

Physiographic expression 148 

Paleontologic character 148 

Structure 148 

Areal distribution 148 

Quaternary system 150 

Subdivisions 150 

Pleistocene series 151 

Subdivisions 151 

FossiUferous marls 151 

Gray sand 154 

' ' Planorbis marl " 155 

Coquina » 155 

" Vermetus rock " 156 

Yellow clay 156 

Stratigraphic position 156 

Thickness 157 

Physiographic expression 158 

Paleontologic character 158 

Structure 158 

Recent series 158 

Alluvial deposits 159 

Lacustrine deposits 159 

'' Vermetus rock " 160 

Oyster reefs 160 

Coral reefs. 160 

Beach deposits 160 

Eolian deposits 160 

Chemical deposits 161 

Human remains 162 

Structure 163 

Early investigations 163 

General character 165 

Southern Florida, by Samuel Sanford 167 

Stratigraphy 167 

Pre-Pleistocene formations 167 

Character and distribution 167 

Well records 167 

Distribution of wells 167 

Palm Beach 168 

Indian Key Channel 168 

Key Vaca 169 

Knights Key 170 

Big Pine Key 170 

Key West 170 

Buck Key 172 

OKgocene series 173 

Miocene and Pliocene series 173 



6 coi^TEMs. 

Part II. — Geology — Continued. 

Southern Florida, by Samuel Sanford — Continued, 

Stratigraphy — Continued. Page. 

Pleistocene series . . -. 174 

Unexposed formations 174 

Exposed formations 175 

General character 175 

Palm Beach limestone 175 

Synonymy 175 

Stratigraphic position 176 

Lithologic character. 176 

Thickness 176 

Physiographic expression 176 

Paleontologic character 177 

Areal distribution 177 

Structure 177 

Miami oolite 177 

Synonymy 177 

Stratigraphic position 178 

Lithologic character 178 

Thickness 179 

Physiographic expression 179 

Paleontologic character 179 

Areal distribution 180 

Structure 180 

Correlation 180 

Origin 180 

Key West oolite 180 

Synonymy 180 

Stratigraphic position 180 

Lithologic character 181 

Thickness 181 

Physiographic expression 182 

Paleontologic character 182 

Origin 182 

Chemical character 184 

Key Largo limestone 184 

Synonymy 184 

Stratigraphic position 186 

Lithologic character 186 

Thickness 187 

Physiographic expression 187 

Paleontologic character 188 

Areal distribution 188 

Lostmans River limestone 189 

Synonymy 189 

Stratigraphic position 189 

Lithologic character 190 

Thickness 190 

Areal distribution 190 

Origin 191 

Correlation of Pleistocene formations 191 

Lithology of Pleistocene beds 192 

Coquina 192 

Sands 193 



^ 



CONTENTS. 7 

I'art II. — Geology — Continued. 

Southern Florida, by Samuel Sanford — Continued. 
Stratigraphy — Continued. 

Pleistocene series — Continued. 

Lithology of Pleistocene beds — Continued. Page. 

Marls 194 

Summary 194 

Thickness of the Pleistocene rock 194 

Recent series. 195 

General character 195 

Peat 195 

Marl 196 

Sand 196 

Coral 197 

Worm rock 198 

Oyster banks 198 

Soils 198 

Structure 199 

Geologic history, by G. C. Matson and Samuel Sanford 199 

Data ' 199 

Oligocene epoch 199 

Vicksburg epoch 199 

Emergence 201 

Apalachicola epoch 202 

Miocene epoch 203 

Physiographic changes 203 

Deposition 204 

Pliocene epoch 205 

Physiographic changes 205 

Deposition 206 

Pleistocene epoch 207 

Uplift 207 

Submergence 209 

Terraces 210 

Southern Florida 211 

Recent epoch 212 

Northern and central Florida 212 

Southern Florida 214 

Topographic changes 216 

Part III. — Underground water 219 

General features, by G. C. Matson 219 

Source 219 

Amount 221 

In the earth as a whole 221 

In Florida 221 

Evaporation 222 

Depth 224 

Water table 224 

Depth of potable supplies 225 

Circulation 227 

Recovery 228 

Natural recovery 228 

Seepage 228 

Springs 228 



8 CONTENTS. 

Part III. — Underground water — Continued. 
General features, by G. C. Matson — Continued. 

Recovery — Continued. Page. 

Artificial recovery. .'. 229 

Wells 229 

Types 229 

Position 230 

Methods of well making 231 

Dug wells ". 231 

Bored wells 231 

Driven wells 232 

Drilled wells... 232 

Methods of raising water 233 

Central and northern Florida, by G. 0. Matson 234 

Artesian water 234 

Artesian requisites 234 

Head 235 

Controlling factors 235 

Head in Florida 236 

East coast 236 

Interior 237 

Southern Florida 237 

West coast 237 

Changes 237 

Natural causes 237 

Artificial causes 239 

Artesian fallacies 241 

Occurrence ' 242 

Water-bearing materials 242 

Character 242 

Sand and gravel 242 

Clay 242 

Shell marl 243 

Limestone 243 

Water-bearing formations 243 

Governing conditions 243 

Oligocene series 248 

Importance 248 

Limestones of the Yicksburg group 248 

Chattahoochee formation 249 

Hawthorn formation 249 

Tampa formation 250 

Alum Bluff formation 250 

Miocene series 251 

Character 251 

^Jacksonville formation 251 

Choctawhatchee marl 251 

Pliocene series 252 

General conditions 252 

Nashua and Caloosahatchee marls 252 

Alachua clay 252 

Bone Valley gravel 253 

Pliocene (?) series 253 

Lafayette (?) formation 253 

Pleistocene and Recent series. 253 



COKTENTS. 9 

Part III. — Underground water — Continued. 

Central and northern Florida — Continued. Page. 

Public water supplies 254 

Surface and underground waters of southern Florida, by Samuel Sanford . . 255 

Source 255 

Water table 255 

Springs 256 

Water-bearing formations 258 

Oligocene 258 

Miocene and Pliocene 258 

Pleistocene 258 

Artesian water 259 

Quality 259 

Relations of fresh and salt water underground 261 

Part IV. — County descriptions 263 

Alachua County, by G. C. Matson 263 

General features 263 

Geology 263 

Water supply 265 

Source 265 

Quality 265 

Development 265 

Baker County, by G. C. Matson 267 

General features 267 

Geology 267 

Water supply 268 

Source 268 

Quality 268 

Development 268 

Bradford County, by G. C. Matson 269 

General features 269 

Geologic formations 269 

Water supply 270 

Source 270 

Quality 270 

Development 270 

Brevard County, by G. C. Matson 273 

General features 273 

Geology 273 

Water supply 275 

Source 275 

Quality 275 

Development 275 

Calhoun County, by G. C. Matson 277 

General features 277 

Geology 278 

Water supply 278 

Source 278 

Quality 278 

Development 279 

Citrus County, by G. C. Matson 280 

General features 280 

Geology 280 



10 C0NTEK5?S. 

Part IV. — County descriptions — Continued. 

Citrus County, by G. C. Matson — Continued. Page. 

"Water supply ^^. 281 

Source .' 281 

Quality 281 

Development 281 

Clay County/by G. C. Matson 283 

General features 283 

Geology 283 

Water supply 284 

Source 284 

Quality 284 

Development 284 

Columbia County, by G. C. Matson 286 

General features 286 

Geology 286 

Water supply 287 

Source 287 

Quality 287 

Development 287 

Dade County, by Samuel Sanford 288 

General features 288 

Geology 288 

Water supply 289 

Source 289 

Springs 289 

Wells 289 

Artesian prospects 292 

De Soto County, by G. C. Matson 294 

General features 294 

Geology 294 

Water supply 295 

Source '. 295 

Quality 295 

Development 295 

Duval County, by G. C. Matson 296 

General features 296 

Geology 297 

Water supply 299 

Source 299 

Quality 300 

Development 300 

Escambia County, by G. C. Matson 301 

General features 301 

Geology 302 

Water supply 304 

Source 304 

Quality 304 

Development 304 

Franklin County, by G. C. Matson 305 

General features 305 

Geology 305 



CONTENTS. 11 

Part IV. — County descriptions — Continued. 

Franklin County, by G. C, Matson — Continued. Page. 

Water supply , ^.... 306 

Source 306 

Quality 306 

Development 306 

Gadsden County, by G. C. Matson 308 

General features 308 

Geology 308 

Water supply 310 

Source 310 

Quality 310 

Development 310 

Hamilton County, by G. C. Matson 312 

General features 312 

Geology 312 

Water supply 313 

Source 313 

Quality 313 

Development 313 

Hernando County, by G. C. Matson 316 

General features 316 

Geology 316 

Water supply 317 

Source 317 

Quality 317 

Development 317 

Hillsborough County, by G. C. Matson 319 

General features 319 

Geology 320 

Water supply 322 

Source 322 

Quality 322 

Development 322 

Holmes County, by G. C. Matson i 325 

General features 325 

Geology. 325 

Water supply 326 

Source 326 

Quality 326 

Development 326 

Jackson County, by G. C. Matson 327 

General features 327 

Geology 327 

Water supply 328 

Source 328 

Quality 328 

Development 328 

Jefferson County, by G. C. Matson 330 

General features 330 

Geology 330 

Water supply 331 

Source 331 

Quality 331 

Development 331 



12 CONTENTS. 

Pabt IV. — County descriptions — Continued. Page. 

Lafayette County, by G. C. Matson 335 

General features 335 

Geology • 335 

Water supply 335 

Source 335 

Quality 335 

Development 335 

Lake County, by G. C. Matson 338 

General features 338 

Geology 338 

Water supply 341 

Source 341 

Quality 341 

Development 341 

Lee County, by Samuel Sanford 344 

General features 344 

Geology 344 

Water supply 344 

Source and quality 344 

Development 345 

Artesian prospects 350 

Leon County, by G. C. Matson 350 

General features 350 

Geology. 350 

Water supply 351 

Source 351 

Quality 352 

Development 352 

Levy County, by G. C. Matson 354 

General features 354 

Geology 354 

Water supply 354 

Source 354 

Quality 354 

Development 355 

Liberty County, by G. C. Matson 357 

General features 357 

Geology 357 

Water supply 358 

Source 358 

Quality 358 

Development 358 

Madison County, by G. C. Matson 359 

General features 359 

Geology 359 

Water supply 359 

Source 359 

Quality 360 

Development 360 

Manatee County, by G. C. Matson 362 

General features 362 

Geology 362 



CONTENTS. 13 

Part IV. — County descriptions — Continued. 

Manatee County, by G. C. Matson — Continued. Page. 

Water supply 363 

Source : 363 

Quality 363 

Development 363 

Marion County, by G. C. Mateon 365 

General features 365 

Geology. 365 

Water supply 366 

Source 366 

Quality 366 

Development 366 

• Monroe County, by Samuel Sanford 370 

General features 370 

Geology 370 

Water supply 370 

Source and quality 370 

Development 371 

Nassau County, by G. C. Matson 373 

General features 373 

Geology ■ 373 

Water supply 374 

Source 374 

Quality 374 

Development 374 

Orange County, by G. C. Matson 376 

General features • 376 

Geology 376 

Water supply 377 

Source 377 

Quality 377 

Development 377 

Osceola County, by G. C. Matson 379 

General features 379 

Geology 379 

Water supply 380 

Source 380 

Quality 380 

Development 380 

Palm Beach County, by Samuel Sanford 381 

General features 381 

Geology 381 

Water supply 382 

Source 382 

Artesian prospects 384 

Pasco County, by G. C. Matson 385 

General features 385 

Geology 385 

Water supply 386 

Source 386 

Quality 386 

Development 386 

Pinellas County 387 



14 CONTENTS. 

Part IV. — County descriptions — Continued. Page. 

Polk County, by G. C. Matson 388 

General features 388 

Geology ' 388 

Water supply 389 

Source 389 

Quality 389 

Development 389 

Putnam County, by G. C. Mateon 391 

General features 391 

Geology 391 

Water supply 392 

Source.. 392 

Quality 392 

Development i 393 

St. John County, by G. C. Matson 394 

General features 394 

Geology 395 

Water supply 397 

Source 397 

Quality 397 

Development 397 

St. Lucie County, by G. C. Matson 398 

General features 398 

Geology .' 398 

Water supply 399 

Source 399 

Quality 399 

Development 399 

Santa Rosa County, by G. C. Matson 401 

General features 401 

Geology 401 

Water supply 401 

Source 401 

Quality 401 

Development 401 

Sumter County, by G. C. Matson 404 

General features 404 

Geology 404 

Water supply 406 

Source 406 

Quality 406 

Development 406 

Suwannee County, by G. C. Matson 408 

General features 408 

Geology 408 

Water supply 408 

Source 408 

Quality 408 

Development 409 

Taylor County, by G. C. Matson 413 

General features 413 

Geology 413 



CONTENTS. 15 

Part IV. — County descriptions — Continued. 

Taylor County, by G. C. Matson — Continued. • Page. 

Water supply ..._„„„ 413 

Source 413 

Quality 413 

Development 414 

Volusia County, by G. C. Matson 416 

General features 416 

Geology 416 

Water supply 418 

Source 418 

Quality 418 

Development 418 

Wakulla County, by G. C. Matson *. . 420 

General features 420 

Geology 420 

Water supply 421 

Source 421 

QuaUty 421 

Development 421 

Walton County, by G. C. Matson 422 

General features 422 

Geology 423 

Water supply 424 

Source .- 424 

QuaUty 424 

Development 424 

Washington County, by G. C. Matson 426 

General features 426 

Geology 426 

Water supply 428 

Source 428 

Quality 428 

Development 428 

Index 431 



Inserts (tables) facing pages 254, 266, 276, 282, 284, 286, 294, 300, 304, 322, 328, 342, 
348, 356, 360, 364, 366, 378, 380, 390, 392, 396, 406, 418. 



76854°— wsp 319—13 2 



ILLUSTRATIONS. 



Page. 

Plate I. General topographic and geologic map of Florida In pocket. 

II. Map of part of WilHston quadrangle, showing sink holes 26 

III. A, Sink hole, Alachua County; B, Sink hole containing pond, 10 

miles southeast of Vernon, Washington County 26 

IV. A, Sink of Santa Fe River; B, Drainage sink of Oclahatchee Lake, 

7 or 8 miles south of Lake Park, Ga 27 

V. Generalized map of Pleistocene terraces of Florida In pocket. 

VI. A, Pleistocene terrace and escarpment bordering St. Marys River 
on Florida side, opposite Traders Hill, Ga. ; B, Old well of Spanish 

type, St. Augustine 32 

VII. A, Beach ridge of coral and shell sand, Knights Key; B, Calcareous 

sand on reef rock 62 

VIII. A, Mangrove key, water's edge; B, Root growth of mangroves south 

end of Key Vaca 63 

IX. A, Section in quarry of Ocala Lime Co. at Ocala; B, Quarry of Ocala 

Lime Co. (old Phillips quarry), 1 mile southeast of Ocala 80 

X. A, Limestone of Tampa formation exposed along Sixmile Creek, a 
quarter of a mile below Atlantic Coast Line Railway bridge, Hills- 
borough County; B, Limestone of Chattahoochee formation on 
Withlacoochee River at New Bridge (or Horn Bridge), 3 miles 
below Georgia & Florida Railway bridge, Lowndes County, Ga. . 94 
XI. A, Contact of Nashua marl and Pleistocene sand, a quarter of a mile 
below Nashua, on St. Johns River; B, Clay unconformably over- 
lying Nashua marl in pit about half a mile south of De Leon 

Springs station 140 

XII. A, Conglomerate of Lafayette (?) formation, resting on sandstone 
of uncertain age, top of Rock Hill, Washington County; B, Rock 
face in coquina quarry, Anastasia Island 148 

XIII. A, Coquina rock on Gulf side of Sarasota Key; B, Turtle Mound, 

an ancient shell mound on North Indian River 154 

XIV. A, Reef rock. Key Largo limestone, showing erosion; B, Quarry in 

Miami oolite 178 

XV. A, Reef rock, Key Largo limestone, coral head; B, Mud cracks in 

crustal layers of Key West oolite 184 

XVI. A, Well at Quincy, illustrating type of bored well and bucket in use 
in Gadsden County; JB, Flowing well at New Smyrna, with pro- 
vision for shutting off water when not in use 230 

XVII. A, Waterwheel for pumping water, Caloosahatchee River; B, Wekiva 

Spring, showing spring and bathhouse 234 

Figure 1. Section near edge of Everglades west of Fort Lauderdale 58 

2. Relation of underground- water level to Silver and Blue springs 224 

3. Relation of underground-water level to surface contour in Suwannee 

and Columbia counties 224 

4. Profile across peninsula of Florida in latitude 29° N 225 

5. Diagram showing importance of choosing proper locations for wells. 230 

6. Conditions governing the occurrence of artesian water in some parts 

of Florida 234 

7. Variation of water level in Johnson well near San Bernardino, CaL. 240 
16 



GEOLOGY AND GROUND WATERS OF FLORIDA. 



By George Charlton Matson and Samuel Sanford. 



INTRODUCTION. 

The geology of Florida has been a subject of investigation for many 
years, for the delightful winter climate of the State early attracted 
to it many scientists who attempted, with varying degrees of success, 
to solve some of the geologic problems. The investigations, however, 
have thus far resulted in only one comprehensive stratigraphic 
report, although many papers have appeared in scientific journals, 
notably in the transactions of the Wagner Free Institute of Science 
and the American Journal of Science. 

The present report, like all similar reports covering large areas, 
contains data derived from many sources. The authors have care- 
fully studied the earlier literature and have compared the different 
views presented, which are here summarized, credit being given to the 
several investigators. The work of W. H. Dall, of the United States 
Geological Survey, has been especially helpful. Mr. Dall made ex- 
tensive investigations of the paleontology of the State and, in 1892, 
published a treatise ^ covering nearly a hundred pages, in which he 
outlined the conditions as they were then known. A later report 
by Mr. Dall ^ is primarily paleontologic, but contains also a summary 
of the geology and the stratigraphy of the State. 

The paleontologic studies of T, Wayland Vaughan, of the United 
States Geological Survey, under whose immediate supervision this 
report has been prepared, in connection with the work of Mr. Dall, 
have also been of great value, because they have formed a basis for all 
subsequent work. Mr. Vaughan examined and identified the fossils 
collected during the progress of the work, and he has very generously 
placed at the disposal of the writers his own extensive notes, accumu- 
lated during many years. The work of other geologists, prominent 
among whom are Dr. Eugene A. Smith, Prof. Angelo Heilprin, and 
Prof. Alexander Agassiz, has added much to the writers' knowledge 
of the geology of Florida. 

1 Correlation papers— Neocene: Bull. U. S. Geol. Survey No. 84, 1892, pp. 85-159. 

2 Contributions to the Tertiary fauna of Florida: Trans. Wagner Free Inst. Sci., vol. 3, pts. 1-6, 1890-1903. 

17 



18 GEOLOGY AND GROUND WATERS OF FLORIDA. 

After the discovery of phosphate in Florida George H. Eldridge 
was sent by the United States Geological Survey to make detailed 
investigations of the deposits. He obtained much valuable data 
but unfortunately did not live to prepare his final report. His note- 
books have been available, however, and have occasionally been 
drawn upon by the writers. 

Aside from incidental references to underground waters in Florida, 
brief summaries of the water resources have been published by the 
United States Geological Survey and by the Florida Agricultural Ex- 
periment Station. Most of the scattered references to Florida waters 
are of historic interest only, but some of the records of deep-well 
borings are important. Four lists of these are worthy of special 
mention. The first two were compiled by Darton,^ the third by 
Fuller, Lines, and Veatch,^ and the fourth by Fuller and Sanford.^ 

Summaries of the underground-water resources of Florida have been 
published by Fuller * and Sellards.^ A report on the ground waters 
of central Florida has recently been published by the State Geological 
Survey.® 

The investigations leading to the present report were made possible 
primarily by the passage of the act incorporating the new State sur- 
vey. The United States Geological Survey was then engaged in mak- 
ing a systematic investigation of the geology of the Atlantic Coastal 
Plain of the United States and with the financial cooperation of the 
new survey was enabled to make a more comprehensive study than 
could have been carried out in a single season by either bureau alone. 

In October, 1907, F. G. Clapp, then employed by the Federal sur- 
vey, began a field study of the stratigraphy and underground water 
resources of northern and central Florida. In November of the same 
year he was joined by G. C. Matson, and the two remained in the State 
continuously until May 1, 1908, visiting nearly every town in the 
northern and central sections and gathering as much data as time 
would permit. At the same time Prof. E. H. Sellards, State geolo- 
gist, and his assistant, Herman Gunter, visited 16 counties in central 
Florida and gathered data on the water supplies. 

The funds available for field expenses having been exhausted, 
Messrs. Clapp and Matson returned to the office about May 1, 1908. 

1 Darton, N. H., Preliminary list of deep borings in the United States: Water-Supply Paper U. S. GeoL 
Survey No. 57, pt. 1, 1902, pp. 21-22; and Water-Supply Paper No. 149, 1905, pp. 25-26. 

2 Fuller, M. L., Lines, E. F., and Veatch, A. C, Record of deep-well drilling for 1904: Bull. U. S. Geol. 
Survey No. 264, 1905, pp. 44-45. 

3 Fuller, M. L., and Sanford, Samuel, Record of deep well drilling for 1905: Bull. U. S. Geol. Survey No. 
298, 1906, pp. 47-50, 195-199. 

4 Fuller, M. L., Contributions to the hydrology of eastern United States, 1903: Water-Supply Paper 
U. S. Geol. Survey No. 102, 1904, pp. 18, 27, 238-275; and Underground waters of eastern United States; 
Water-Supply Paper U. S. Geol. Survey No. 114, 1905, pp. 159-163. 

6 Sellards, E. H., Occurrence and use of artesian water: Bull. Florida Agr. Ex. Station No. 89, 1907, pp. 
1-113. 

6 Sellards, E. H., A preliminary report on the underground water supply of central Florida: Bull. Florida 
Geol. Survey No. 1, 1908, pp. 1-103. 



ACKNOWLEDGMENTS. 19 

On July 1, 1908, Mr. Clapp resigned from the United States Geo- 
logical Survey, and the work of preparing the manuscript for the 
report on the northern and central parts of the State was intrusted to 
Mr. Matson. Before tendering his resignation Mr. Clapp prepared 
the topographic map of the State and drew up a tentative outline of 
the paper published in the Second Annual Report of the Florida Geo- 
logical Survey.^ 

Shortly after the appearance of the State report Thomas Wayland 
Vaughan published a paper entitled "A contribution to the geologic 
history of the Floridian plateau," ^ containing a resum^ of the geo- 
logic history and valuable information concerning the influence of 
depth and temperature of ocean waters, and the action of ocean 
currents in the development and history of the peninsula of Florida. 

The geologic information contained in the earlier papers has been 
incorporated in the present report, with such revisions as were 
deemed essential to make it suitable for a Water-Supply Paper. The 
results of field work by Mr. Matson while in the employ of the General 
Land Office during the winters of 1909-10 and 1910-11 have been 
utilized in the preparation of additional discussions of the Pleistocene 
geology. Some important changes in both the text and map of the 
earlier report have also been made possible by Mr. Matson' s recent 
field work. The base map accompanying both reports was prepared 
by the United States Geological Survey. 

At the time when the field work for this report was begun Samuel 
Sanford was engaged in geologic work for the Florida East Coast 
Railway, and the task of investigatiag the geology of the keys and of 
the southern end of the State was intrusted to him. 

The interest and cooperation of the people of Florida have rendered 
this work a pleasure, and the authors wish here to make public 
acknowledgment of the numerous favors and courtesies extended 
them in the field and office. Several persons deserve particular men- 
tion, among them being Dr. J. N. MacGonigle, of Miami; Mr. Goff 
and several other officials of the Florida East Coast Railway, 
for affording opportunities to visit the extension of the railroad 
during the process of its construction. Mr. Frank Clark, of Gaines- 
ville, furnished introductions which greatly facilitated the investiga- 
tions ; Dr. DeWitt Webb, of St. Augustine, and Dr. Crill, of Palatka, 
have interested themselves in the work. Many well drillers have 
furnished logs and records, adding valuable data to the knowledge of 
the stratigraphy. Capt. Alexander Near, of Eau Gallic; Mr. H. C. 
Haven, of De Land; Mr. W. D. Holcomb and Mr. Edward Pettigrew, 
of Manatee; Mr. H. W. Pearce, of Arcadia; Mr. H. Walker, of St. 

1 Matson, G. C, and Clapp, F. G., A preliminary report on the geology of Florida, with special refer- 
ence to the stratigraphy: Second Ann. Kept. Florida Geol. Survey, 1909, pp. 28-173. 

2 Pub. Carnegie Institution of Washington No. 133, 1910, pp. 99-185. 



20 GEOLOGY AKD GEOUK0 WATERS OF FLORIDA* 

Augustine; Mr. Wm. E. Hughes, of Charleston, S. C; J. E. Ingraham, 
of the Florida East Coast Eailway; J. C. Meredith, formerly construct- 
ing engineer, and W. J. fcome, constructing engineer, of the Key 
West extension, rendered special assistance. 

Many others, who can not be mentioned on account of lack of space, 
have given substantial assistance. A number of citizens have inter- 
ested themselves in acting as guides and in furnishing specimens and 
samples from wells. The officials of the Atlantic Coast Line RaUroad, 
the Seaboard Air Line Railway, the Florida East Coast Railway, and 
the Louisville & Nashville Railroad, in Jacksonville, Wilmington, 
Norfolk, and Louisville, have allowed access to their profiles and other 
records, which gave valuable information for use in the construction 
of the topographic map of the State. (See PI. I.) 



^ 



PART I.— GEOGRAPHY. 

NORTHERN AND CENTRAL FLORIDA. 

By G. C. Matson. 
NATXTRE OF COUNTRY. 

The area described in this report comprises all the State of Florida. 
(See PL I, in pocket.) It forms a part of the province commonly 
known as the Coastal Plain — a broad tract of relatively low land 
which extends from New York to Mexico, rising gradually from the 
coast to a height of a few hundred feet and for the most part appar- 
ently flat or gently rolling. In Florida the shores are low and 
swampy, variations in the altitude amounting to only a few feet in 
several miles. Farther inland the surface is more rolling, and is in 
some places hilly, but the relief is nowhere great. Most of the sur- 
face is sandy, though in a few localities the soil contains consider- 
able clay. The sandstones, clays, shales, and limestones of the older 
formations are nearly everywhere only a few feet beneath the surface. 

RELIEF. 

Although Florida is a region of comparatively slight relief, its sur- 
face presents considerable diversity, ranging from a nearly level 
plain in the coastal region and the Everglades to a deeply dissected 
upland in the northern part of the State, where it is trenched by 
steep-walled valleys, and to a highland in the peninsula, where it 
shows many more or less rounded depressions separated by narrow 
divides. Altitudes within the State range from sea level to more 
than 200 feet above at places on the ridge that forms the center of 
the peninsula and to about 300 feet above, at the western end of the 
State near the northern boundaries of Gadsden, Walton, Santa Rosa, 
and Escambia counties. 

The topographic map (PL I) is intended to show the approximate 
areas of land which lie above and below certain altitudes. The 
datum plane is mean sea level, and the contour Lines connect points of 
equal altitude at intervals of 50 feet. The map embodies the results 
of the earlier topographic surveys, the river surveys of the United 
States Army Engineers, and the several railroad surveys, together 
with a large number of barometric determinations made during the 
field work. Although the exact location of the contours is in places 
more or less uncertain, it is believed that they are sufficiently accu- 

21 



22 GEOLOGY AND GROUND WATERS OF FLORIDA. 

rate to give a good idea of the relative areas of different altitudes and 
to present a general plan of the broader topographic features of the 
State. The small scale of the map made it necessary to omit such 
minor details as sink holes, valleys of small streams, narrow ridges, 
and small more or less isolated elevations. The United States Geo- 
logical Survey has already published detailed maps of seven contigu- 
ous quadrangles (Arredondo, Citra, Dunnellon, Ocala, Panasoffkee, 
Tsala Apopka, and Williston), comprising an area of about 1,800 
square miles, situated in the central part of the peninsula, and to 
these the reader is referred for local information. 

The southern part of the peninsula, comprising an area about 150 
miles long and over 100 miles in average width, lies in general less 
than 50 feet above sea level. Narrow strips of lowland also border 
the Atlantic and Gulf coasts. The valleys of the streams do not rise 
above the 50-foot contour for a considerable distance from the coast, 
and one of them (St. Johns River) is nowhere more than 30 feet 
above tide. 

The uplands of the peninsula and the adjacent part of north Flor- 
ida are separated into two more or less distinct parts by Ocklawaha 
River. Beginning southeast of Arcadia, a belt of high land, very 
irregular in shape, extends northward to Summit on the Atlantic 
Coast Line Railroad, and separates the Kissimmee River drainage 
basin from that of the streams to the west. At Lakeland, Brooks- 
ville, and several other points this upland rises more than 200 feet 
above sea level. 

Another broad, irregular upland, stretching northward from Ockla- 
waha River to the Georgia line, includes a considerable tract more 
than 150 feet above sea level and forms the divide between the 
Atlantic and Gulf drainage basins. Its narrowest part is along the 
western boundaries of Clay and Duval counties, where it forms the 
long north-south divide known as Trail Ridge. This upland includes 
Lake City, at an altitude 201 feet above sea level, and Highland on 
Trail Ridge at an altitude of 210 feet. Near the Georgia line the 
upland broadens into the Okef enokee swamp, which occupies a large 
area in Georgia and extends^ short distance into Florida. The western 
slope of the highland is cut by Santa Fe River and its tributaries, and 
its eastern slope is deeply dissected by the tributaries of St. Johns and 
St. Marys rivers. 

Near the State line in the northern and western parts of Florida lies 
a narrow upland which has been deeply dissected by several streams. 
On its seaward side this highland in many places descends rather 
abruptly to the low coastal region. Its highest points are near the 
northern line of the State, where considerable areas rise above the 
250-foot contour. Notable examples of this upland are seen in 
Gadsden County and in the counties west of Choctawhatchee River. 



GEOGRAPHY OF NORTHERN AND CENTRAL FLORIDA. 23 

Tallahassee, the capital of the State, stands about 205 feet above sea 
level, on a remnant of the upland which has been isolated by erosion. 
East of Apalachicola River the railroad stations at Monticello, Mid- 
way, and Quincy are all reported to be over 200 feet above sea level, 
and west of this river are some of the highest points in Florida. 
Between Argyle and Deerland, and at several points north of Crest- 
view, all on the Louisville & Nashville Railroad, the profiles show 
that considerable tracts rise above the 200-foot contour. Argyle, 
De Funiak Springs, and Mossyhead are also above 250 feet. It ap- 
pears probable that at some localities near the Alabama line the 
surface may be somewhat higher. According to the list of altitudes 
furnished by the Seaboard Air Line Railway, Mount Pleasant is 301 
feet above sea level. This is the highest accurately determined point 
recorded in Florida. 

DRAINAGE. 

RIVERS. 

The changes in relative positions of land and sea which have aJBPected 
the drainage of Florida are so closely interwoven with the general 
geologic and physiographic history that their full discussion is left 
till later. (See pp. 199-218.) Here it is only necessary to note the 
general character of the streams and to state briefly the factors which 
have produced existing conditions. 

Some of the rivers are confined to the coastal lowlands, where they 
assumed their courses in consequence of the initial slope of the land 
as it emerged from the sea; they are therefore known as consequent 
streams. The channels of many of them are winding. Wherever 
there were depressions in the sands lakes were formed, and some of the 
consequent streams consist of a chain of such lakes joined by more or 
less well-defined channels. To this class belongs the Kissimmee- 
Caloosahatchee system with its numerous lakes. 

Consequent streams that have removed the thin mantle of surficial 
sand and cut into the older formations belong to the class known as 
superimposed streams. Thus Caloosahatchee River, which in parts 
of its course has eroded a channel through the surface formations into 
the underlying Pliocene marls, is superimposed upon these older 
formations. In like manner St. Johns River north of Sanford has 
been superimposed upon the Pliocene and probably the Miocene rocks. 
Manatee and Aucilla rivers have in parts of their courses been super- 
imposed upon the Oligocene formations. In Florida there are many 
other examples of consequent and superimposed streams and many 
rivers which, like the St. Johns, are in part consequent and in part 
superimposed. 

The rivers that cross both the older and younger geologic formations 
existed before the sands that form the surface of the lowlands were 



^4 GEOLOGY AKD GBOUND WATEHS OF FLOEIDA. 

deposited, and originally they entered the sea at the edge of the 
present highland belt. Where they crossed the highland these 
streams now have broad, deep valleys floored with a deposit of 
alluvium and bordered by many prominent bluffs. In their courses 
across the upland they take directions determined by the slope of the 
surface, but in most places they have removed the surficial formations 
and cut deeply into the older rocks upon which they are superim- 
posed. As the coastal belt emerged from the sea by successive addi- 
tions to its landward margin, these streams gradually extended their 
channels across this new land and hence became in part what is 
commonly known as extended streams. On the Coastal Plain they 
flow in broad shallow trenches bordered by low banks of sand, and in 
some places they have removed the Pleistocene sand and eroded 
channels in the underlying limestones and marls. The most impor- 
tant extended streams of the State are Escambia, Blackwater, Yellow, 
Choctawhatchee, Apalachicola, Ochlockonee, Aucilla, Withlacoochee, 
Hillsboro, Peace, and St. Marys rivers. With the possible exception 
of Escambia River, all these streams are in part superimposed upon 
the Pliocene or older geologic formations. 

After the deposition of the younger geologic formations and the 
extension of the streams across the newly emerged land, a slight sub- 
mergence caused a shortening of the streams and permitted the sea 
water to ascend the river channels for several miles from the coast. 
In this way the lower parts of the stream valleys were transformed 
into estuaries which contain brackish water and are affected by the 
tides. The exact length of these estuaries or tidal portions of the 
rivers differs in different streams, and even in a single river it may 
change with the strength and direction of the wind, strong onshore 
winds raising the height of the water and forcing the sea water farther 
upstream and offshore winds having an opposite effect. 

LAKES AND SWAMPS. 

Although the State of Florida is crossed by many large rivers, it 
contains numerous tracts of land which are very imperfectly drained 
and are occupied by lakes or swamps, some of them being of consider- 
able size. The most noteworthy undrained area is in the southern 
part of the peninsula where the Everglades and adj acent lowlands form 
a nearly impenetrable wilderness. In this lowland tract lies Lake 
Okechobee, one of the largest and most interesting lakes in the south 
Atlantic States. According to Sanford the Everglades nowhere rise 
more than 25 feet above sea level, and the slope of the surface is so 
gentle that much of the water which falls during the rainy season is 
held for a time in broad, shallow ponds and marshes that carry excel- 
lent growths of saw grass and other aquatic plants. These plants, 



GEOGRAPHY OP I^ORTHEHN Al^r> CENTRAL FLORIDA. 25 

by their partial decay under water, have formed extensive peat and 
muck deposits several feet in thickness. 

Smaller swamps and marshes are found in all parts of the State 
but are especially numerous in the belt of lowland that borders the 
coast. In the highlands occupying the northern portion of the State 
they are smaller and less numerous. In the coastal belt there are also 
many small lakes and ponds, some of them permanent but most of 
them lasting only during the rainy season. Few exceed 2 or 3 feet in 
depth. 

In the central part of the peninsula and in some localities near the 
northern boundary of the State are lakes and swamps which appear 
to be the result either of unequal depression of the surface sands or of 
solution of the subjacent limestone and consequent lowering of the 
surface. (See p. 74.) Some of the lakes are shallow and resemble 
those of the coastal belt, but others are deep basins partly or wholly 
inclosed by a rim of rock. Many of the smaller swamps contain peat 
or muck, but few of the deposits attain any great thickness and many 
of them form only a thin coating of partly decomposed vegetable 
matter mingled with more or less sand. 

TOPOGRAPHIC PROVINCES. 

CHARACTERISTIC FEATURES. 

Florida may be divided into three topographic provinces— the 
upland . region of the peninsula (commonly known as the "Isike'^ 
region), the lowland, and the coast. Lakes, of course, are not con- 
fined to the upland or "lake" region. Generally speaking, however, 
they are grouped in two more or less distinct areas, those lying in 
rock basins occupying the upland and those lying in shallow depres- 
sions in the sand in the coastal and southern lowlands, though many 
in the highlands lie in depressions in the sand and some small ones 
in the lowlands are known to occupy rock basins. The highland 
area of the peninsula, however, where rock basins predominate, has 
commonly been known as the lake region, and for convenience this 
desimation is retained. 



rrin 



LAPLAND OR LAKE REGION. 
UNDERGROUND DRAINAGE. 



le lake region comprises a type of topography common to all 
limestone areas that have been sufficiently elevated to permit the 
formation of large underground streams. The character of the 
surface is well shown by Plate II, which is a part of the Williston 
sheet of the topographic atlas of the United States. The numerous 
depressions shown in the plate are known as sink holes, and in order 



26 GEOLOGY AliTD GEOUND WATEES OF FLOEIDA. 

to understand their origin it is necessary to consider the development 
of the underground drainage. 

Caverns. — This region is underlain at no great depth by several 
hundred feet of porous limestone of Vicksburg age. Where surface 
water bearing carbonic acid derived from decaying organic matter 
enters this rock, it gradually dissolves the limestone and forms 
underground channels. A large part of the mineral matter thus 
removed by the underground water is carried to the surface and, 
entering the rivers, is transported to the sea. Sellards ^ estimates 
the amount of solid matter removed in this manner, basing his cal- 
ciilations on the amount of mineral matter contained in solution in 
the waters of eight of the large springs of the State. These springs 
emerge from caverns in the underlying limestone and are fed by the 
rain falling on the surrounding areas. The percentage of mineral 
matter in solution was determined by analysis and the volume of 
flow was estimated. By this method Sellards estimated that Silver 
Spring brought to the surface 340 pounds of mineral matter per 
minute. The figures for the other springs were different, but all 
were large. With a conservative estimate of the average mineral 
content of the spring water (219 parts per million) and the assump- 
tion that about one-half ^ the rainfall of Florida entered the earth 
and removed this amount of material, Sellards reached the conclu- 
sion that the amount of solution was sufficient to remove about 
400 tons per square mile each year. If evenly distributed this would 
lower the surface of the limestone about a foot in 5,000 or 6,000 
years. The concentration of this solution along certain beds or 
channels of active circulation would permit the formation of large 
underground passages in comparatively brief geologic time, and it 
has dissolved out many channels, known as caverns, which are already 
hundreds of feet in diameter and several miles in length. A level 
surface and a porous soil, such as that of the lake region, favor the 
development of caverns because most of the rainfall sinks into the 
earth instead of flowing off over the surface. 

Sink holes. — As solution progressed the cavern roofs became 
weakened at numerous points and collapsed, forming the depressions 
known as sink holes. (See PL II.) In some areas these depressions 
are so numerous that they occupy a large part of the surface and 
give the region its characteristic topography. Splendid examples 
of ancient sinks, such as the Devils Mill Hopper, are to be found in 
different parts of the State, and the formation of sinks in different 
parts of the lake region by the collapse of cavern roofs is within the 
memory of persons now living. A good example of a recently formed 

1 Sellards, E. H,, A preliminary report on the underground water-supply of central Florida: Bull. Florida 
Geol. Survey No. 1, 1908, pp. 47-48. 

2 Idem, p. 16. 



U. S. GEOLOGICAL SURVEY 


WATER- 


SUPPLY PAPER 319 PLATE III 


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£. SINK HOLE CONTAINING POND, 10 MILES SOUTHEAST OF VERNON, WASHINGTON 

COUNTY. 



U. S. GEOLOGICAL SURVEY 



WATER-SUPPLY PAPER 319 PLATE IV 




A. SINK OF SANTA FE RIVER. 




B. DRAINAGE SINK OF OCLAHATCHEE LAKE, 7 OR 8 MILES SOUTH OF LAKE PARK, GA. 



^ 



GEOGRAPHY OF I^^OETHERN AND CENTRAL FLORIDA. 27 

sink is to be seen on the road between High Springs and the ''sink'' 
of Santa Fe River. A second example is a new sink near Alachua 
sink, Alachua County, where a section of the surface 100 feet in 
diameter has recently dropped over 30 feet, leaving an open hole 
filled with water. (See PI. Ill, A.) In the phosphate region, a 
large quantity of water, which has been used in mining operations, 
is allowed to enter the ground. That this water may have a notice- 
able effect in weakening the roofs of the underground-drainage chan- 
nels is shown by the following quotation from the unpublished notes 
of George H. Eldridge : 

Since the mining of phosphate has been undertaken many sinks have been formed 
near the settling ponds or along the line of drainage from the mine washers. The 
writer has in the morning passed over a stretch of apparently firm road which on 
his return at night had given way to a chasm 40 feet across, in which earth, shrubs, 
and trees had been engulfed and into which water was pouring down to an under- 
ground passage in the weirdest conceivable way. At one of the Southampton mines 
the floor of the old pit and an adjoining area of overlying sand has sunk several feet, 
leaving a rift in the earth 4 or 5 feet across. 

If the bottom of the sink does not contain an opening the water 
that accumulates after rainfall wiU in most places escape to the 
underground stream by seepage, but if the amount of rainfall is 
too great to be carried away in this manner it accumulates in lakes 
or ponds. The level of the standing water in such ponds fluctuates, 
rising after each rainfall and gradually sinking during dry weather. 
Hundreds of lakes in Florida belong to this class. Some sinks 
have openings in the bottom which connect directly with under- 
ground streams, and into these openings the surface streams plunge, 
carrying loads of sediment and other debris. This sediment probably 
aids the underground stream in enlarging its channel by mechanical 
wear, but sometimes it accumulates in such quantities as partly or 
even whoUy to close the passage, causing the surface water to form 
a lake or pond. (See PI. Ill, B.) Examples of open sinks receiving 
the discharge of surface streams are common, conspicuous among 
them being the sink of Santa Fe River (PL IV, A), the sink of Chipola 
River, the Lake sink in Jefferson County, the sink of Oclahatchee 
Lake (PL IV, B), and the Alachua sink near Gainesville. 

The Alachua sink is important because it illustrates some of the 
changes which sink holes undergo. In the early days of the State, 
this sink, which receives the drainage of a large stream crossing 
Paynes Prairie, appears to have been in about the same condition 
as it is to-day ; ^ later, owing to the closing of the outlet,^ perhaps by 
logs and other rubbish, a large lake was formed. About 1891 the 
sink reopened and the basin was drained, effectually ending the 
steamboat traffic that had developed on the lake. 

1 Bartram, William, Travels, 1791, pp. 187 et seq. 

2 DaU, W. H., Correlation papers— Neocene: Bull. U. S. Geol. Survey No. 84, 1892, pp. 94-96. 



28 GEOLOGY AKD GEOUND WATERS OF FLORIDA. 

In some parts of the caverns the water enters through the open- 
ings in the Hmestone and evaporates, leaving a deposit of calcium 
carbonate. By gradual accretion these deposits may form large 
pendants (stalactites) hanging from the roof or walls. When the 
water falls to the f3oor of the cavern and evaporates, its remaining 
carbonate builds up projections known as stalagmites. The deposits 
in caverns are frequently highly ornamental and form the chief 
attraction for visitors. 

Sometimes the underground streams form new passages and 
abandon portions of their old channels, and it is the abandoned 
channels that are commonly visited by travelers. In Florida, only 
a few caverns have been explored and none are reported to be highly 
ornamented. The most important caverns noted during the field 
work are located near Marianna, Ocala, and Alachua. The one near 
Alachua is known as Warren Cave and is said to be well worth 
visiting. 

Natural bridges . — Where the underground stream emerges, it forms 
a spring, and as the roof of the cavern falls it leaves an open channel 
through which the spring drains to some surface stream. By a 
continuation of this process, the underground stream is transformed 
into a surface stream. Where a segment of the roof of the under- 
ground channel remains after the parts above and below have fallen, 
a natural bridge results. Natural bridges may also be formed in 
another manner where the river water gradually works its way 
into an underground passage, establishing an underground stream 
beneath the floor of the surface channel. As such a channel is 
gradually enlarged by solution and mechanical wear, more river 
water passes through it. FuiaUy, the surface channel may be 
unoccupied except during high water, or if the underground passage 
is large enough the surface channel may be entirely abandoned. 
A surface channel may also be produced across a natural bridge 
whenever the underground passage is partly obstructed. 

There are many natural bridges in Florida, small ones being 
reported near Homosassa, north of ClarksviUe, in northern Walton 
County, and in many other localities. Large natural bridges occur 
on Chipola Eiver above Marianna, on Santa Fe Kiver northeast of 
High Springs, and on several other rivers. The natural bridge on 
Chipola River is submerged during high water, and a broad shallow 
surface channel crossing the natural bridge near High Springs is 
said to carry a portion of the flood waters of Santa Fe River (PI. 
IV, A). The breadth of the surface channel near High Springs 
suggests that the natural bridge of Santa Fe River may have been 
formed by the second method outlined above. The natural bridge 
of Chipola River was submerged at the time the field work was done 
in that vicinity, so that no observations could be made. However, 



GEOGRAPHY OF N-ORTHERN AND CENTRAL FLORIDA. 29 

the broad valley of the river above the bridge indicates that the 
upper part of the river has been a surface stream for a long period. 
As natural bridges in such rocks are not apt to endure for long 
periods, it appears probable that this one may also have been formed 
by the second method. 

SPRINGS. 

The great development of underground drainage in many parts 
of the State has given rise to many springs at places where streams 
emerge from subterranean channels. The number of such springs is 
very great. In size they vary from mere seeps to discharges which 
gi^e rise to creeks and rivers large enough to float good-sized passen- 
ger and freight steamers. The best known and largest is the Silver 
Spring in Marion County, which gives rise to a large stream of 
remarkable clearness and beauty. The water emerges from a basin 
over 35 feet deep in a stream (Silver Spring Eun) that is about 50 
feet in average width and more than 9 feet in minimum depth in the 
center of the channel. The water is so clear that objects lying on 
the bottom are distinctly visible. 

Ajnong the other large springs of the region are Wekiva Spring, 
the source of the river of the same nanae; Sulphur Spring, near 
Tampa; Suwannee Sulphur Spring, near Suwannee; Blue Spring, near 
Juliet Station; Blue Spring, near Orange Junction; Green Cove 
Spring, on St. Johns Eiver; Itchatucknee Spring, near Fort White; 
Poe Spring, near High Springs ; Crystal Eiver Springs, the source of 
Crystal Eiver; Weekewachee Spring, near Bayport; and Newland 
Spring, near Falmouth. All these springs are well known and 
many of them are very large. They are supplied with water by 
the limestones of the Vicksburg group, which are everywhere porous 
and in many places cavernous. 

A spring at Tarpon Springs is worthy of special mention because 
it appears to be in part supplied with water from a small lake. The 
water emerges at the bottom of the bay a few feet below mean tide 
level. On the opposite side of the town is a small lake which is with- 
out surface outlet and apparently occupies a sink hole. Usually the 
flow of this spring is comparatively insignificant, but at times the 
discharge is enormous. Observations made upon the lake just 
before and after one of these outbursts of the spring appear to show 
that the lake discharges water into the spring through some under- 
ground channel, for the surface of the lake is said to have been 
lowered several inches while the spring was flowing rapidly. 

Aside from the large springs mentioned many others yield large 
quantities of water, and springs of moderate size exist in nearly all 
parts of the State. Some of the smaller springs are supplied with 
water from the superficial sands, but many of them derive their 
supplies from the limestones. 



30 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

EROSIONAL FEATURES 

In west Florida and in parts of peninsular and north Florida the 
surface configuration has been largely determined by the erosion of 
surface streams. However, sink-hole topography is common as far 
west as Walton County, and many of the depressions are occupied by 
small lakes. 

From Leon County westward the major streams cross the upland 
in wide, level-floored valleys bordered by well-defined bluffs. The 
depth of these valleys is due to the erosive action and the width to 
the meanderiQg of the streams. Most of them contaiu a deposit of 
sand and mud, which rises but little above the level of the streams 
and is partly overflowed when the latter are high. 

The small streams of the uplands flow in narrow valleys with 
steep walls and high gradients. In most of these valleys erosion has 
not extended far from the main streams and many of the divides 
between the principal rivers are comparatively level. Near the 
rivers the areas of level land become smaller and the number and 
depth of the valleys increase until the surface is largely reduced to 
steep slopes. It is also worthy of note that the amount of dissection 
increases toward the south. Thus most of the io.x^ \,el tracts of 
upland are found near the northern line of the State. At its southern 
edge the upland in places descends quite abruptly to the coastal 
belt bordering the Gulf of Mexico. In some places, however, the 
transition to the coastal lowlands is by a gradual slope. 

LAKES. 

The uplands are for the most part covered by a few feet of gray 
sand, which masks the minor inequalities of the erosion topography. 
Moreover, it is in many places difficult to determine whether shallow 
depressions are sink holes or are merely irregularities in the surface 
of the sand. However, the sink-hole origin of deep depressions such 
as the lake at De Funiak Springs appears to be unquestionable. 

SAND DUNES. 

Sand dunes and ridged are common, especially along the southern 
edge of the uplands, but few of them are more than a few feet in 
height. Wind-blown sands are probably much more widespread 
than is indicated by the surface topography, the heavy precipitation, 
together with the abundant vegetation, preventing the development 
of extensive dunes. 

LOWLAND. 

The coastal region of Florida comprises a belt of lowland little of 
which rises above the 100-foot contour and much of which is only a 
few feet above high tide. Its emergence from the sea took place 



GEOGRAPHY OP NORTHERN AND CENTRAL FLORIDA. 31 

after the drainage of the uplands had been well developed and the 
rivers gradually extended their channels across it as new areas were 
added to the land. 

STREAMS AND PONDS. 

The Pleistocene sands, which form a large part of the surface in the 
coastal region, slope gently toward the sea and are in places crossed 
by sniall streams flowing in shallow valleys. MLuor irregularities in 
the sui^ace of the sand have resulted in the shallow lakes and ponds 
that cover large areas during the rainy season. The difference in 
elevation between the bottoms of many of these ponds and the 
surface of the surrounding areas is less than 2 feet. 

RIDGES. 

Scattered throughout the coastal region are small areas of higher 
land which in some places resemble sand ridges and in other places are 
very irregular in form. Some of them contain a core of rock covered 
by a thin mantle of sand, but many appear to be composed. entirely of 
sand. These areas represent the higher parts of the original sea floor 
and their positions were determined by the inequalities in the surface 
of the underlyinp" rock or by unequal deposition of the sands. 

SAND DTJNES. 

A large part of the surface of Florida is covered by a few feet of 
gray sand. Along the coast this sand has in some places reduced the 
original inequalities of the surface and in others has increased them 
by forming sand dunes and ridges. However, few of the dunes and 
ridges are more than a few feet in height and hence they have little 
effect on the topography. 

TERRACES. 

General features, — Bordering the coast and extending into the Val- 
leys of all the large streams are a series of terraces presentmg generally 
level surfaces bordered by low, seaward-facing scarps. These plains 
have been grouped into three divisions and as they represent succes- 
sive stages in the Pleistocene physiographic history of Florida they 
will be discussed at some length. They form broad plains but little 
dissected by stream valleys and are so poorly drained that marshes 
and lakes are common. The surface of the lowermost terrace ranges 
in altitude from sea level to about 40 feet above it, and includes both 
Recent and Pleistocene deposits; the second terrace ranges from 40 
to 60 feet above sea level; and the third from 60 to 100 feet above 
the same datum plane. They are known, respectively, as the Pen- 
sacola, the Tsala Apopka, and the Newberry terrace, the first-named 
being the youngest. (See PL V, in pocket.) 

These terraces are for the most part constructed of lithologically 
similar materials, and this fact together with the absence of char- 
76854°— wsp 319—13 3 



32 GEOLOGY AND GKOUND WATERS OF FLORIDA. 

acteristic fossils makes it necessary to rely on the topography for 
their discrimination. The general distribution of the terraces is 
shown on Plate V. This map does not show their occurrence in 
detail, for, in the absence of suitable topographic maps, it is in many 
places difficult to decide on the correlation of more or less isolated 
plains. The failure to delineate narrow terraces along some of the 
streams is necessary because of the small scale of the map. 

The Pleistocene terraces were formed during submergence of 
portions of the land beneath the sea. The maximum amount of 
submergence was sufficient to permit the sea to encroach on all 
the land less than 100 feet above the present level of the sea. The 
relations of the land and water remained nearly uniform at some 
stages long enough to permit the waves to erode and redeposit the 
materials from the underlying formations. The erosive action of 
the waves of the Pleistocene sea produced low seaward-facing scarps 
(see PI. VI, A) and at the same time the materials eroded from the 
older formations were redeposited in the form of plains that are 
locally several mUes wide. The surfaces of these plains are not 
everywhere level, but few inequalities exceed 2 or 3 feet, except 
where subsequent erosion has changed the topography. 

The Pleistocene terraces were originally slightly irregular and the 
result of unequal deposition on an eroded surface. The most strik- 
ing topographic features are the sink holes in the limestones that lie 
near the surface in the west-central part of the peninsula. Some of 
the minor variations are the low sand ridges, lying nearly parallel to 
the coast, which were built by the waves of the Pleistocene sea. 
Their recognition is exceedingly difficult because in most places they 
rise less than 5 feet above the adjacent surface. Depressions of 
varying size and shape are numerous, but they are seldom noticed 
except during the rainy season, when they are transformed into 
ponds and marshes. 

The Pleistocene terraces extend up the river valleys, where they 
are composed in part of estuarine and in part of fluviatile materials; 
the two types merge into each other and are not everywhere dis- 
tinguishable. Inasmuch as the deposition of fluviatile sediments 
shifted seaward during freshets and landward when the rivers were 
low and sluggish, the fluviatile deposits should dovetail with the 
estuarine. 

Newberry terrace. — The Newberry terrace, which is composed of 
light-gray or yellow sand with local deposits of clay, forms a plain 
rising from about 70 feet to more than 100 feet above sea level. Its 
formation was brought about by an encroachment of the sea upon 
the land and its size depends upon the amount of erosion and deposi- 
tion accomplished during that submergence, less whatever portion 
has been subsequently removed by erosion. Before the time of 



U. S. GEOLOGICAL SURVEY 






WATER-SUPPLY 


^APER 319 


PLATE VI 




■^■^-yi- 


''' 

t 






An 




|tt 


M 


HI 




IHI 


? ' 


j^' 1 T^^^ 




1 




■ 


^^ 


I^^^B^:'^#a^^H^^^HHf^ ^,^:iiV \'.'Am 


1 



^. PLEISTOCENE TERRACE AND ESCARPMENT BORDERING ST. MARYS RIVER ON FLORIDA 
SIDE, OPPOSITE TRADERS HILL, GA. 




B. OLD WELL OF SPANISH TYPE, ST. AUGUSTINE. 



GEOGRAPHY OF NORTHERN AND CENTRAL FLORIDA. 33 

this encroachment Florida had suffered considerable erosion and 
the Tertiary formations had been subjected to some tilting and 
folding, so that the materials composing the terrace rest on the 
eroded surfaces of formations ranging in age from the Vicksburg to 
the Pliocene, and their relation to the Tertiary formations is every- 
where unconformable. 

Weathering had been active before the invasion of the Pleistocene 
sea, and the terrace consists largely of the weathered portions of the 
subjacent rocks. Limestone is generally absent, the prevailing 
materials being sand with some clay and a little chert, especially 
where the underlying rocks belong to the Vicksburg group. No 
fossils have been found in the exposed portions of the Newberry 
terrace, and it is doubtful if it contains many. Some of the Pleisto- 
cene shells obtained from well borings at Kissimmee probably came 
from the layers near the base of this terrace, but they are not unlike 
those found in the younger Pleistocene terraces. The flu via tile por- 
tions of the terrace are somewhat coarser than the marine portions and 
contain a much larger proportion of colored sands and clays, especially 
in the northern part of the State. 

The Newberry terrace encircles the Tertiary formations, forming 
an almost unbroken band about them. Its presence at several 
points in northern Marion and southern Alachua counties has led to 
the belief that a Pleistocene strait separated the higher portion of 
the peninsula from the upland to the north, thus transforming the 
central portion of the peninsula into an island. Other smaller areas 
to the west were probably separated from the central area by narrow 
straits. However, these conclusions need to be confirmed by more 
detailed observations than have as yet been possible. At the Georgia 
boundary the materials of the Newberry terrace, and probably those 
of the Tsala Apopka terrace, merge into the deposits of the Okefenokee 
formation.^ 

Few exposures give adequate sections of the Newberry terrace 
and well records rarely shed much light on its thickness. A few 
exposures in the phosphate rock region show that the sands range 
from 1 to 20 feet in thickness. However, the maximum thickness 
of the sands and clays forming this terrace may exceed 100 feet in 
some of the valleys where considerable erosion preceded the Pleisto- 
cene submergence. 

Tsala Apoplca terrace. — The Tsala Apopka terrace is composed 
chiefly of sand, with clay at some locaHties. These deposits, resting 
unconformably upon Tertiary formations, form a plain rising 40 to 
60 feet above sea level. The encroachment of the sea at the time of 

1 Veatch, Otto, and Stephenson, L. W., Geology of the Coastal Plain of Georgia: Bull. Georgia Geol. 
Survey No. 26, 1911, p. 45. 



34 GEOLOGY AKD GEOUND WATERS OF FLOEIDA. 

the formation of the Tsala Apopka terrace was not so extensive as 
during the development of the Newberry terrace. The stratigraphic 
relations of the materials comprised in the two terraces have not 
been observed, though the materials composing the Tsala Apopka 
terrace ma}^ rest upon the eroded edges of the Newberry terrace. 
The Tsala Apopka terrace materials have been observed resting upon 
eroded surfaces of the beds of Tertiary age at the type locahty, in 
the Tsala Apopka lake region, and at many other places. As in the 
case of the Newberry terrace, the underlying beds include the differ- 
ent formations from the OHgocene to the Pliocene. 

Sand is the principal constituent of the Tsala Apopka terrace, 
although some clay is found in places and fragments of chert occur 
where the underlying beds are of Oligocene age. In general, the 
sands are gray, but in northern Florida red and yellow sands are 
found in many of the stream valleys. The deposits composing the 
Tsala Apopka terrace probably average 25 to 30 feet in thickness, but 
this estimate is uncertain because good exposures are rare. 

The Tsala Apopka terrace is well developed in the vicinity of the 
lake of that name, and it extends southward nearly to Punta Gorda, 
thence east and north along the west side of St. Johns River valley. 
An area of the terrace lies east of St. Johns River, but its outlines 
are very imperfectly known. The Paynes Prairie plain, as well as 
the plain partly occupied by Orange Lake, are regarded as portions 
of this terrace, and a broad branch extends up Ocklawaha River. 
The upland portion of the State is surrounded by this terrace, and it 
probably extends beyond the State line in the valleys of the princi- 
pal streams. 

Pensacola terrace. — The Pensacola terrace is a broad plain, rising 
less than 40 feet above sea level, and apparently including two divi- 
sions, one being less than 20 feet above, and the other from 20 to 40 
feet above sea level. There has been no attempt to differentiate 
these two subdivisions, and on the map (PI. V) they are not sepa- 
rated from the Recent deposits. This terrace merges with the plain 
that forms the surface of the Satilla formation in Georgia.^ The Pen- 
sacola terrace presents topographic conditions similar to those of the 
Satilla plain, but the composition of the materials entering into the 
construction of the two plains are unlike. 

The Pensacola terrace is largely constructed of sand with local 
beds of clay but in the southern portion of the State includes im- 
portant limestone beds, several of which are described by Sanford. 
A large amount of coquina underlies the sand that forms the sur- 
face of the terrace from St. Augustine southward. Aside from the 
limestones the terrace materials are sand, except at a few locaUties 

» Veatch, Otto, and Stephenson, L. W., Geology of the Coastal Plain of Georgia: Bull. Georgia Geol. 
Survey No. 26, 1911, p. 434. 



GEOGEAPHY OF NORTHEBN AKD CENTRAL FLORIDA. 35 

where they include marls containing shells of land and marine animals. 
The thickness of the sands and limestones is variable, ranging from, 
less than a foot to more than 100 feet, the average being probably 
greater than in any other Pleistocene terrace. Where the base of 
the terrace materials is exposed, it is found resting unconformably 
upon the older beds, but good exposures are rare. 

The Pensacola terrace occupies a wide belt surrounding all the 
older formations. It extends the entire length of St. Johns River 
valley and occupies an area nearly 150 miles long in the southern 
end of the peninsula. The Everglades and adjacent marshy lowlands, 
together with the depressions occupied by numerous lakes, lie within 
the area included in the Pensacola terrace. The area occupied by 
this terrace on the west side of the peninsula is smaller than on the 
east because the winds and currents of the west coast are less favor- 
able for adding to the land area than those on the east coast. On the 
southern edge of western Florida the terrace broadens near some of 
the large streams and in areas where the direction of the winds is 
favorable to the extension of the land seaward. The estuarine and 
fluviatile portions of the Pensacola terrace are so narrow that it is 
not practicable to show it along the river valleys except near the 
coast. Along some of the larger streams this terrace may extend 
beyond the northern boundary of the State. 

THE COAST. 

The extensive coast line of Florida presents a great variety of topo- 
graphic forms, for the most part shaped by waves, tides, shore cur- 
rents, and living organisms, chiefly corals. The configuration of the 
shore is dependent on the relative importance of these agencies. 

CORAL REEFS. 

Coral reefs are restricted to an area near the southern end of the 
peninsula, and it was to this area that much of the earlier geologic 
work was devoted. Sanford discusses the formation of the Florida 
keys and the adjacent portion of the mainland in the light of his 
recent studies in that region. Here it is only necessary to call atten- 
tion to the fact that coral reefs have been of minor importance in the 
development of the peninsula ; in fact there appears to be no reason 
to suppose that reefs have been important on the west coast or north 
of the north line of Dade County on the east coast. 

SUBMERGED CONTINENTAL BORDER. 

Reference to the charts of the United States Coast and Geodetic Sur- 
vey shows that the depth of the water along the Florida coast is in few 
places more than 10 fathoms. Submarine contours (PI. V, in pocket) 
which have been compiled from the charts previously mentioned, 



36 GtJOLOGY AKD GROUND WAFERS OF FLORIDA. 

show the general relations of the submarine portions of the Floridiatl 
plateau to the land surface. In 1910 these relations were fully dis- 
cussed by Vaughan/ and consequently only a few facts will be con- 
sidered in this report. From the present shore line the sea bottom 
slopes gently to a depth of 100 fathoms, and at that depth the descent 
becomes abrupt. The submarine area less than 100 fathoms in depth 
is regarded as a portion of the continental mass, and is more 
closely related to the land than to the deep-sea bottom beyond the 
100-fathom line. An uplift of 600 feet would add to the land surface 
all the area inclosed by the 100-fathom curve. Reference to Plate V 
will show what a large increase in the land area would result from 
such an uplift. 

Within the area circumscribed by the 10-fathom contour are large 
areas where the water is shoal. It would take an uplift of only 60 
feet to bring the land inclosed by this curve above sea level. From 
soundings this submerged area is known to have a gentle slope sea- 
ward, and its outer margin is comparatively regular. This would 
give to the land surface a much more regular outline than it now has, 
and, according to Vaughan,^ would increase the area of the land about 
one- third. 

A study of Plate V shows that the position of the present land sur- 
face is excentric on the Floridian plateau as outlined by the 100- 
fathom curve. The 100-fathom curve is farther offshore on the west 
side of the peninsula than on the east side. Not only does the land 
lie near the east edge of the plateau but in the vicinity of Jupiter and 
thence southward the land actually extends nearly to the 100-fathom 
contour. Two factors are thought to be responsible for the excentric 
position of the peninsula upon the continenfcal shelf. First, there has 
been differential movement resulting in a depression of the west coast, 
carrying some of the land beneath the sea. This is shown by the 
narrowing of the belts of outcrop of the younger formations and the 
apparent absence of other formations on the west side of the penin- 
sula. Second, the east coast is being rapidly extended by the large 
amount of sediment supplied to it by waves acting under the influence 
of the strong northeasterly winds. The effect of this is well shown 
by Cape Canaveral, as well as by the numerous bars that are trans- 
forming the coastwise straits into lagoons. Evidence is not wanting 
to show that such processes have been active in the past, for ancient 
bars and lagoons that have been filled with sediments may be recog- 
nized at numerous places. 

1 Vaughan, T. W., A contribution to the geologic history of the Floridian plateau: Pub. Carnegie Inst. 
Washington No. 133, 1910, pp. 107-114. 

2 Idem, p. 109. 



GEOGRAPHY OF NORTHERN AND CENTRAL FLORIDA. 37 

BARS. 

In tlie shallow water at some distance from the shore the waves 
gradually build bars which rise nearly to the surface. As the material 
is derived from the sea bottom the bars vary with the character of 
the latter. At present the prevailing material on both the east 
and west coasts is sand, often considerably admixed with shells, and 
the bars now being formed consist largely of sand with a small pro- 
portion of shell fragments. In comparatively recent geologic time, 
the beach materials on some parts of the coast appear to have been 
largely shells, which were built into bars and afterwards cemented to 
form coquina. Some layers of sand and a considerable percentage 
of silica in the coquina show that terrigenous material was never 
entirely absent, though it was often of minor importance. In the 
shallow water along the exposed shores, both of the mainland and the 
islands, currents are formed which transport the beach materials 
and build them into numerous forms. Among these are the bars 
which are found across the entrance of all the bays, constituting one of 
the important obstacles which confronts the Army engineers in their 
endeavor to make the rivers and harbors accessible to steamers. 

On the east coast, where the prevailing currents move southward, 
the bars are commonly extended by additions to their southern ends. 
On the Gulf coast, the dominant currents appear to be in the opposite 
direction and the bars are usually building by successive additions 
to their northern ends, though an eastward current of some importance 
may be inferred from the position of the bar at the entrance to St. 
Andrews Bay. 

SOUNDS. 

Behind the shore bars are narrow bodies of shallow water which, 
on the east coast, are commonly known as rivers, though they might 
more appropriately be termed sounds. To this class belong such 
bodies of water as Halifax and Indian rivers. As the sounds become 
more nearly surrounded by the growing bars they change into lagoons 
which are in turn gradually filled with silt and thus transformed into 
marshes. Mosquito Lagoon and Lake Worth on the east coast are 
excellent examples of lagoons, and marshes are numerous along both 
the east and west coasts. 

About 20 years ago an attempt was made to open a passage for 
steamship navigation by deepening the sounds and lagoons. This plan 
was successful, but in recent years the channels have been allowed 
to become obstructed by sand bars and oyster reefs. In the last few 
years interest in this ^'inside" channel has been revived, and it is 
now proposed to extend the passages northward to New Jersey. 



38 GEOLOGY AND GEOUKD WATEES OF FLORIDA. 

INLETS. 

Where drainage from the land enters a sound or partly inclosed bay, 
the water escapes through a narrow passage in the bar known as an 
inlet. As the bars are built under the influence of a prevailing cur- 
rent, the inlet is gradually shifted in the direction of growth, and after 
a time the opening becomes so obstructed that a new inlet is formed 
during high water. Usually the inlets are formed near the head of 
the bar and their direction of movement on the Atlantic coast is 
southward and on the Gulf coast northward or westward. At 
Jupiter, on the east coast, an opening is sometimes dredged near the 
north end of the bar and this opening gradually shifts toward the south. 
It has been found that the inlet remains open much longer when the 
opening is made toward the northern end of the bar than when it is 
made farther south. 

TIDAL RUNWAYS. 

At ordinary high tide the level of the water in the bays and sounds 
is raised from 1 to 2 feet above the normal low-water level. If at 
the same time a strong wind is blowing toward the land the water 
rises much higher. When the tide recedes, a seaward current is formed 
which scours the bottom and sides of the channels. Frequently the 
water pours through some low gap in a shore bar, thus helping to 
form a passage. Many of the inlets across the Florida bars are formed 
in this way. To the erosive action described above the name 'Hidal 
scour " is applied.^ Gulliver thinks that the channels near Cedar Keys 
present an e:j^ample of tidal runways produced by tidal scour, and 
he designates them the '^western Florida type." At the mouth of St. 
Johns River and elsewhere along the South Atlantic and Gulf coasts, 
the Army engineers have constructed dams to narrow the runway so 
that the effect of the tidal scour will keep open a channel deep enough 
to permit the entrance of large vessels. 

CAPES. 

Many of the important capes of Florida appear to have been built 
of sand deposited by currents moviag along the shore. Cape Cana- 
veral on the east coast was formed where the easterly trend of the 
current caused the southward-moving current to move outward 
from the coast into the deeper water where the velocity of the water 
was checked, causiag it to deposit some of its load of sand. From the 
outward end of the cape there projects a long narrow spit of sand, 
which rises nearly to the surface. The seaward end of this spit is 
often bent into a hook by the action of the current. 

On the west coast the northward-moving current encounters the 
islands near the west end of St. Vincent Soimd, and turning westward 

1 Gulliver, F. P., Shore-line topography: Proc. Am. Acad. Arts and Sci., vol. 24, 1899, pp. 180-181. 



GEOGRAPHY OF KORTHERN AKD CENTRAL FLORIDA. 39 

forms Cape San Bias. Cape St. George at the western end of the 
island of the same name, and Southwest Cape, west of Apalachee 
Bay, appear to have been formed in a similar manner. All of these 
capes are gradually being extended seaward by the continual addition 
of material transported along shore by the currents. Many minor 
projections usually known as points have originated in practically 
the same manner as the larger capes. In 1898 Gulliver ^ studied the 
origin of Capes Canaveral and San Bias, and designated them ^'current 
cuspate forelands.'' 

SOILS. 

ORIGIN AND CHARACTER. 

The soils of Florida are almost all derived from the sandy Tertiary 
and Pleistocene formations; and, since the gray Pleistocene sand is 
the most widespread of the surface deposits, it naturally gives rise 
to the soils over the greater portion of the State. The soils of the 
Lafayette (?) formation occupy considerable areas in northern and 
western Florida, and they form the subsoil in many localities where 
the Pleistocene sands are thin. Both the Alachua clay and the Pliocene 
marls are so thinly covered in some parts of peninsular and west 
Florida that they form part of the subsoil. In some areas, where ero- 
sion has been especially active. Pliocene and Pleistocene have both 
been removed, leaving the older geologic formations exposed to form 
the soils ; but such areas are confined to the uplands of the penin- 
sula and west Florida. On the uplands residual materials formed 
by the weathering of the Oligocene formations lie so near the surface 
that they become a more or less important part of the soil or subsoil 
or both. 

Peat and muck soils occupy a large area in the southern part of the 
peninsula and smaller areas in several parts of the State. Their 
greatest development is in the Everglades, but they are found in 
many other localities where swamps exist. They consist of organic 
matter mixed with more or less inorganic material, such as sand and 
clay. These soils are of recent origin and are still being formed, 
especially over a large area south of Lake Okechobee, where the sur- 
face is very low and flat and the drainage imperfect. 

Pleistocene sands form the soil below the 100-foot contour in nearly 
aU of peninsular Florida and extend to the margin of the uplands in 
northern and western Florida. The soils of the Lafayette ( ?) forma- 
tion are largely confined to the upland areas near the northern 
boundary of the State. They do not form large unbroken tracts 
but occur in more or less isolated areas where the post-Pliocene sands 
are absent. In many localities the overlying sands are so thin that 

1 Gulliver, F. P., op. cit., p. 180. 



40 GEOLOGY AKD GEOUlSTD WATERS OP FLORIDA. 

the Lafayette ( ?) deposits form an essential part of either the soil or 
the subsoil, even where the surface materials are younger. 

Pleistocene marls and coquina, in a more or less decomposed state, 
form the subsoil at numerous places along the east coast and along 
the west coast south of Bradentown. Areas where these Pleistocene 
marls lie near enough to the surface to be considered part of the 
soil are much more restricted than is their geologic distribution. 

In the central part of the peninsula, especially northwest of Gaines- 
ville, the Alachua clay lies so near the surface that it forms a part of 
the subsoil, but so far as is now known it does not enter into the 
formation of the surface soil. Over much of the area where this 
formation occurs it is too deeply buried to be considered a part of 
the soil. 

On the north bank of Manatee Eiver, in the vicinity of EUenton, 
there are some areas of land, valuable for truck gardening, where the 
residual clays left by the solution of the limestone of the Tampa 
formation form very good soils. In some places these clays contain 
more or less Pleistocene sand and numerous fragments of angular or 
subangular chert. Doubtless other localities exist where the residual 
products of this limestone lie near enough to the surface to form 
part of the soils, but the areal distribution of these soils is not yet 
known. 

Decomposition products of the limestones of the Chattahoochee 
formation and the Vicksburg group form parts of the soils in locali- 
ties where younger deposits are absent, but over large areas 
they are too deeply buried beneath the younger geologic forma- 
tions to be important in soil formation. It is the proximity to the 
surface of marls or residual products of the rocks of the Vicksburg 
group which is regarded as the source of the fertility of many of the 
^'hammock" lands near the west coast, and it is doubtless the 
presence of such materials near the surface which accounts for the 
excellent growth of timber in places on the peninsula where the sur- 
face soil is very poor. 

SOIL TYPES. 

In 1897 Whitney ^ made a general examination of the Florida 
soils. He says: 

The principal types of soils examined were the first, second, and third quality of 
high pine land; the pine flats or so-called ''flat woods"; the light hammock, the gray 
or heavy hammock, the mixed land, the heavy marl hammock; the pineapple land; 
the Etonia scrub, the spruce-pine scrub; and the Lafayette formation. 

Since the publication of Whitney's report, detailed soil surveys 
have been made in the vicinity of Gainesville and in Escambia County. 

1 Whitney, Milton, A preliminary report on the soils of Florida: Bull. Bur. Soils No. 13, U. S. Dept. 
Agr., 1898, p. 7. 



GEOGfeAJ^HY OF NOETHEKN AND diSl^TfeAL FLORIDA. 41 

In this detailed work the soils were classified by their physical prop- 
erties, origin, and topography, texture being considered the most 
important characteristic. The principal types recognized were sands, 
fine sands, sandy loams, and fine sandy loams. Subordinate types 
were loams, silt loams, clays, mucks, and meadow. These types 
have, with some exceptions, been grouped into three series and cor- 
related with similar soils elsewhere in the Coastal Plain. Aside from 
these general types are the Gainesville and Gadsden sands, so named 
by the Bureau of Soils of the Department of Agriculture, and some 
other types which have not yet been correlated. 

The clay and loam soils of Florida cover a very small area and are 
not of great importance. The clay soils are chiefly small tracts in the 
neighborhood of streams and are not tilled; in this connection it 
should be borne in mind that much of what is commonly called clay 
in northern and western Florida is to be classified as a sandy loam, be- 
cause, though more or less plastic, it contains sand as its most impor- 
tant constituent. The sand or sandy loam soils, which cover the 
greater part of Florida, may be subdivided into a large number of 
types, all of which have certain general characteristics. When brought 
under cultivation their natural productivity is commonly low, but they 
respond quickly to proper treatment and can be made to produce 
large crops, which grow rapidly and mature early. These charac- 
teristics, when linked with a subtropical climate, make the produc- 
tion of early fruits and vegetables very profitable. In order to pro- 
cure the best results it is necessary to exercise skill and judgment in 
the treatment of the soils, and in some places to expend considerable 
money for fertilizers. There is apt to be a deficiency of moisture on 
some of the sands and sandy loams, and hence irrigation is sometimes 
practiced. 

Fertilizers are used in nearly all parts of the State, the amount and 
kind used in the different localities being governed by the nature of 
the crops grown and the experience of the most successful farmers. A 
striking example of the productivity of a sandy soil properly tilled 
is furnished by the yield of pineapples from a ridge of sand near Fort 
Pierce. The value of barnyard refuse and legumes as fertilizers is 
recognized in some localities, but their use should be much more 
extensive. Some recent experiments of the Department of Agricul- 
ture ^ are of interest, as they show that lime, which is not generally 
used on Florida soils, may add greatly to the productivity of certain 
types of the sand and sandy loam soils. 

The peat and muck soils of Florida have not been extensively used 
because they are in swampy areas, which require drainage. Exten- 
sive drainage operations are in progress in the Everglades, and if these 
are continued large areas of peat soil will be available for cultivation. 

1 Soil survey of Escambia County, Florida: Field Operations Bur. Soils, U. S. Dept. Agr., 1906, p. 348. 



42 GEOLOGY AND GEOUlsri) WAT:fillS OF FLORIDA; 

The natural productivity of the peat and muck soils of Florida has 
seldom been determined, but, judging from the experience of farmers 
in other States, it is safe to predict that the everglade soils are destined 
to take rank among the best lands of the State for the production of 
certain crops. Moreover, experience in several other States has shown 
that such soils seldom require the addition of complete fertilizers, 
such as are used on sandy soils. In fact, the addition of small quan- 
tities of salts of potassium should usually be sufficient to cause a peat 
or muck soil to produce good crops, though possibly in some areas the 
addition of phosphates would be necessary. These facts are im- 
portant, because it will cost much less to fertilize the peat and muck 
soils than is now being expended on the sandy soils. 

GEOGRAPHY OF SOUTHERN FLORIDA. 

By Samuel Sanpord. 
LOCATION AND AREA. 

The term southern Florida is here made to include, for convenience 
of description, the portion of the peninsula with its bordering islands 
or keys lying south of a roughly northeast-southwest line extending 
from the north line of Palm Beach County on the east coast past the 
south end of Lake Okechobee to the mouth of San Carlos Bay on the 
west coast. The piece of mainland thus arbitrarily cut off is 140 
miles in extreme length, north and south, and 120 miles in maximum 
width, east and west. Its area is about 7,300 square miles, of which 
6,000 square miles are swamp or land so low as to be covered with 
water during the rainy season, from June to October, or, near the 
coast, by unusually high spring tides. The total number of the keys 
is unknown, but their area is here estimated at 300 square miles. 
(See PI. I, in pocket.) 

GENERAL FEATURES. 

Growing coral reefs extend along the Florida coast for over 200 
miles and are found nowhere else in the continental limits of the 
United States. Because of the reefs and the teeming marine life of 
the surrounding waters, southern Florida has attracted attention for 
over 50 years and has been visited by a number of eminent scientists 
who have described and discussed the main features of the keys and 
the southeast shore of the mainland. Owing to the difficulties of 
travel in this region and its comparative remoteness and inaccessi- 
bility before the building of the Florida East Coast Railway, these 
visitors confined their observations largely to the reefs, the shore line 
of the keys, and the edge of the mainland in the vicinity of Biscayne 
Bay. 

In 1907 and 1908 the writer had an opportunity to study in detail 
some features of the topography and geology and their relation to 



GEOGRAPHY OF SOUTHERN FLORIDA. 43 

underground waters that were not so evident in former years as they 
are to-day. Between 1896, the year of two important contributions 
to the geology of the region — the papers by Alexander Agassiz ^ on 
the elevated reef and by Griswold ^ on the southern Everglades — and 
1909, when the geology was described in detail in the second annual 
report of the State geologist, the railroad had been completed 
from Palm Beach to Miami and from Miami to Knights Key. At 
the mouth of Miami Kiver, where only a few houses stood at the time 
of Griswold's visit, there is now a city of over 5,000 inhabitants, from 
which radiate miles of excellent macadam roads. What was then a 
barren wilderness now includes thousands of acres of truck farms and 
orange and grapefruit plantations. The result to the geologist from 
this transformation is a great increase in the easily obtainable rock 
evidence. Wells, quarries for road metal, and railroad borrow pits 
make the compiling of geologic data along the east coast vastly 
easier than it was in 1895. Even on the relatively remote west 
coast, from Cape Sable north, there are more settlements to-day than 
there were then, and with the coming of the motor boat the exploration 
of the shallow and tortuous passages characterizing that coast has 
been much facihtated. 

The larger portion of the interior is included in the great saw-grass 
swamp of the Everglades. Though repeatedly crossed by troops in 
the Seminole War and well known to many whit» men, hunters of 
alligators and plume birds, living on its borders, this expanse of 
water and sedge-covered muck had until 1907 been visited by few 
geologists and traversed by none. Griswold's account of what he 
saw toward the south end of the Everglades remained for years the 
best description of the more noteworthy features of the topography 
and geology of the region. Now, however, the drainage and recla- 
mation work carried on by the State is yielding evidence that the 
indi^adual explorer, from the physical difficulties to be overcome, 
could not possibly hope to obtain. 

In a general review of the salient features of the topography of 
southern Florida it is convenient to consider the mainland, the 
keys, and the shore line separately. 

Taken as a whole the topography of the Florida mainland has all 
the aspects of infancy. Drainage is defective; sloughs, shallow ponds, 
and lakes abound. Most of the interior is a swamp; no well-defined 
river systems nor stream valleys exist ; and some of the short rivers 
that flow from the Everglades into the Atlantic are, where bedrock 
comes a few feet above sea level, characterized by rapids in their 
upper courses. 

1 Agassiz, Alexander, The elevated reef of Florida: Bull. Mus. Comp. Zool. Harvard Coll., vol. 28, No. 2, 
1896, pp. 29-51. 

2 Griswold, L. S., Notes on the geology of southern Florida: Bull. Mus. Comp. Zool. Harvard Coll., 
vol. 28, No. 2, 1896, pp. 52-59. 



44 GEOLOGY AND GKOUND WATERS OF FLORIDA. 

TMs infantile aspect is due to two causes, one the actual recency 
of deposition of the beds, consolidated and unconsolidated, that con- 
stitute the land surface, and the other the slight elevation of the beds 
above sea level since deposition. The rocks have had relatively 
little time to decay, and there has been no elevation of the land high 
enough or long enough to give streams an opportunity to erode val- 
leys and establish well-marked drainage systems. 

The shore-line topography is more varied; in places its forms are 
those of infancy and in places those of youth or adolescence, these 
differences in aspect being determined by the influence of opposing 
factors — those that tend to extend the land's edge irregularly and 
those that smooth shore lines into long sweeps and easy curves. 

The relations between land and water on any coast are inconstant 
and ever varying. Not only is the shore a line of battle between the 
forces that destroy and those that build up the land but geologic 
history shows that changes of level are the rule, that the lands or the 
oceans slowly rise or fall during long periods of time, parts of the sea 
bottom becoming dry land and parts of the land being invaded by the 
ocean. In places these movements are rapid enough to be proved by 
human records. Where highlands border the ocean invasion is slow; 
where coasts are low it is relatively swift. The transitions of coast 
lines and the changes resulting from slight elevations or depressions 
of coast are factors of high importance in contemplating the present 
shape of the land mass of southern Florida. 

As has been pointed out by Agassiz, Dall, and others, the present 
Florida mainland is but the top of a vastly greater submarine plateau, 
the southeastern and southern edges of which are near the present 
shore line, and the western edge many miles to the west. Hence, we 
may regard the present outline of the Florida mainland as a mere 
accident. Though stable enough when measured in terms of human 
life, it is ephemeral when compared with the duration of a geologic 
period. A depression of 50 feet would cover all the area considered 
in this report, except the tops of a very few sand hills and ridges; an 
elevation of 50 feet would extend the shore line but little on the east, 
though making dry land of Biscayne Bay; on the south it would dry 
the Bay of Florida; and on the west it would extend the land for 30 
miles west of the entrance to Shark River and 20 miles west of Cape 
Romano. 

The keys or islands that fringe the coast of southern Florida, or form 
the great arc that ends in the Tortugas, are of several types, but for 
the larger part are alike in being lower than most of the mainland. 
Except for some beach ridges and dunes, the general elevation of the 
keys is less than 10 feet, and hundreds of keys are merely mud flats 
hidden by mangroves. 



GEOGRAPHY OF SOUTHERN FLORIDA. 45 

THE MAINLAND. 
SUBDIVISIONS. 

Although the surface of the south Florida mainland has slight relief, 
it yet shows considerable variety of type. A detailed study of its 
forms is beyond the province of this paper, but certain surface 
features will be discussed at some length because of their intrinsic 
importance, because of the attention given them by previous writers, 
and because a general understanding of the topographic types is 
essential in the study of the recently deposited formations and is nec- 
essary to a consideration of underground-water supplies. 

Southern Florida lies low. The average elevation of the surface 
is below 20 feet and over long stretches the ground is almost a dead 
level. The general slope of the surface is south, though elevations 
along the east coast may average 10 feet higher than along the west 
coast. This is shown by the drainage of Lake Okechobee, the greater 
length of the west coast rivers, and the trend of the river courses, 
features that are considered individually on succeeding pages. 

In consequence of the slight relief, the imperfect drainage, and the 
resulting accumulation of surface water during the rainy season, small 
differences in elevation have a marked effect on vegetation and make 
it possible roughly to divide the mainland into pineland and swamp. 
The pineland includes the hammocks, isolated patches whereon grow 
hardwood trees of several genera, and many of the prairies or grassy 
tracts; the swamp land includes the coastal swamps with their char- 
acteristic growths of sedges or black and red mangroves. 

Owing to the low relief the line of demarcation between swamp and 
pineland is extremely irregular. In many places it is not a line but a 
variable width of prairie, which may be 2 feet under water at the end 
of a rainy season, but which in most years gets so dry during the 
winter months that tomatoes and other garden truck can be grown 
on it at a profit without artificial drainage. 

As Matson has stated (p. 35), practically all of southern Florida 
lies within the boundaries of the lowest of the three terraces or 
terrace plains that may be differentiated within the State. This 
lowest terrace, which has a maximum altitude of 40 feet, Matson has 
designated the Pensacola terrace. 



I 



PINELANDS. 

AREA AND DISTRIBUTION. 



The pinelands of southern Florida are not remarkable by reason of 
the size of the trees, the thickness of growth, nor the yield of good 
timber per acre, but as they include the larger portion of the surface 
lying above what may be termed normal water level they are impres- 



46 GEOLOGY AND GEOUKD WATERS OF FLOEIDA. 

sive from their extent. Their total area is a matter of conjecture, for 
though the pinelands have been surveyed by the United States Land 
Office, the township maps give an imperfect idea of the actual extent 
of the timber. In round figures perhaps 1,300 square miles are to 
be regarded as pineclad. 

The pinelands of the eastern coast extend for the most part as a 
narrow belt between the Everglades and the coastal swamp from the 
north line of Palm Beach County to 12 miles southwest of Homestead. 
This belt is widest at the north, where it may be 20 miles across, and 
is much narrower south of Jupiter Inlet, where it is about 6 miles 
wide, varying in width from 2 to 8 miles and taperiag to its south- 
western extremity. West of the Everglades the pines are more 
irregularly distributed; at Naples they grow to the shore of the Gulf; 
along the north line of Monroe . County they grow in more or less 
disconnected areas separated by narrow and broad strips of cypress; 
between Cape Romano and the mouth of Lostmans River they lie 
from 5 to 15 miles back of the outer face of the network of keys that 
constitutes the apparent shore line. South of Lostmans River there 
is no pineland. 

As the trees grow on areas of very different topographic aspect, 
the pineland of southern Florida may be divided according to the 
character of its relief into dimes, rolling sand plains, rock ridges, and 
flat lands. 

DUNES. 

Character. — Dunes as here considered are purely eolian accumu- 
lations and do not include deposits of sand that owe their rehef 
wholly or in part to the action of water, whether that of currents 
or of waves. Dunes are sharply differentiated from beach ridges, 
those coastal accumulations of sand and other loose material in the 
shaping of which waves and wind-driven spray took part. Thus some 
of the ridges facing the ocean at Palm Beach are not considered to be 
true dunes. Moreover, in this discussion the term dune is applied 
to ridges that are at least 4 or 5 feet higher than the general level of 
the sand near by. 

The dunes are composed of medium fine quartz sand, varying in 
tint from pale ^^ellow to orange or to light reddish brown. This 
sand is rather angular and some of it can be broken down to finer 
grains by rubbing between the fingers. Fossil shells are rare, if 
present at all; none were seen by the writer in a rather careful inspec- 
tion of sections through several dunes. The different tints of the 
sand are not, according to the writer's observations, arranged in dis- 
tinct bands, nor is the sand everywhere plainly stratified. However, 
the color tends to increase with depth below surface, thus causing 
the gradation seen in a section through a dune to follow the surface 
contours. In many places the shades of yellow and brown are mottled 



GEOGEAPHY OF SOUTHERN FLORIDA. 47 

or blotched. Streaks of gray sand, possibly caused by the decay ol 
pine tree roots, extend from the surface to varying depths into the 
yellow and reddish sands below. In some dunes the sands toward 
the center have been so cemented by iron oxide as to form irregularly 
rounded masses of hard rock. 

Perhaps the most noteworthy feature of the dunes of southern 
Florida is their quiescence. If cleared of pine timber and palmetto 
scrub they grow good pineapples, but even when bare their sands are 
little moved by the prevailing winds. The blasts of a hurricane may 
affect them somewhat, but certainly nowhere in southern Florida is 
there any such movement as is characteristic of dunes in active 
growth; no leeward march overwhelms trees and threatens dwellings, 
and no such drift is in progress as can be seen at Cape Henry, Va., 
and at other points on the Atlantic coast. Instead of burying 
forests the dunes of southern Florida, where not cleared, are covered 
with scrub or large pine trees. In short, they are quiescent. 

Evidently, therefore, the dunes were formed during a time when 
conditions were different from those now prevailing — a time when 
the topographic and the climatic conditions favored sand drift. 
Though near the coast the dunes are not directly related to the present 
shore line, but, as shown by the fringes of swamp and the off-lying 
keys, to another shore line now below sea level. The significance of 
these facts as bearing on the post-Tertiary history of southern 
Florida will be discussed later. 

Distribution. — In southern Florida the larger dunes lie near the coast. 
East of the Everglades and Lake Okechobee they reach south to New 
River as a discontinuous series of irregularly distributed mounds and 
ridges, in places separated by considerable intervals of fiat or gently 
roUing country or by stretches of shallow water; but in few places do 
they extend more than a few miles inland and in few do they face 
the open ocean. South of New River there are, so far as the writer 
knows, no true dunes; certainly there are none on the 150-mile chain 
of keys that extends from Biscayne Bay to the Marquesas, the nearest 
approach to them being many low indistinct ridges and mounds, 
nowhere 8 feet above mean sea level. These are most pronounced 
along stretches of beach facing breaks in the living coral reef, par- 
ticularly where the water near the shore has more than average 
depth, or rather where the seaward slope of the bottom is greatest. 
These low heaps of sand, from theu* position, may be the work of the 
waves quite as much as of the wind, and in fact most, if not all, of 
them are true beach ridges. Their outlines may probably have been 
modified slightly by wind-borne sand, but their main features are 
clearly due to wave action, particularly to the waves that break on 
the exposed beaches during a hurricane, when tides 4 feet or more 
76854°— wsp 319—13 i 



48 GEOLOGY AND GKOUND WATERS OF FLORIDA. 

above mean higli-water mark inundate the keys and facilitate the 
formation of unusually high inshore waves. 

Along the east coast the position of the more prominent dunes near 
the shore is indicated on the Coast Survey charts. A noteworthy 
succession of ridges extends in an approximately north-northwest 
direction from 2 miles north of the dune on which stands Jupiter 
lighthouse, at the north side of Jupiter Inlet, to and past Hobe 
Sound station on the Florida East Coast Railway; just back of the 
station the summit of one has a height of 63 feet above sea level. 
Back of the lighthouse at Jupiter the top of one dune is perhaps 45 
feet high. North of Hobe Sound station the dune belt veers to the 
westward and dies away within 3 miles. There are no large dunes 
along the railroad from Hobe Sound to the north line of Palm Beach 
County, and, according to report, no large ones north of the northern 
end of the Hobe Sound belt and no high ground between it and 
Kissimmee. 

South of Jupiter Inlet dunes are numerous but occur as disconnected 
mounds or ridges and not as continuous or contiguous ridges. A 
typical dune, 47 feet high, at West Palm Beach, according to report, 
contained masses of rock. There are dunes 20 feet high near Palm 
Beach. Isolated dunes and ridges near the shore between West 
Palm Beach and Jupiter are shown by the Coast Survey charts. 
South of West Palm Beach the dune belt lies farther inland, though 
generally parallel to the seashore, and the more prominent dunes 
have not been mapped. There is a fine dune ridge near the east side 
of Lake Osborne, /about a mile west of Lantana station. Isolated 
dunes of diminishing height occur to the south, the southernmost 
one of any prominence known to the writer beiag Pine Island, in the 
Everglades back of Fort Lauderdale, 6 miles from their eastern mar- 
gin. The belt of country containing the prominent dunes south of 
West Palm Beach probably in no place exceeds 5 miles in width. 

On the west coast of southern Florida, dunes are not nearly so 
numerous as on the east coast and are more irregularly distributed; 
like the east-coast dunes they are found near the shore rather than 
inland. 

The best-developed dune system seen by the writer on the west 
coast is the one that covers parts or the whole of several islands near 
Caximbas Pass. It extends east from the south end of Caximbas 
Island in a disconnected line having somewhat the shape of the 
Greek letter i2, the total length being about 8 mUes. Just back of 
Caximbas post office, at the west end of the system, there is a dune 
about 35 feet high. A mile to the northeast another ridge, having 
a maximum height of 60 feet, is said to be the highest in the system. 

There are no dunes on the islands near the mouth of Caloosahatchee 
River; where from the configuration of the present coast line they 



GEOGRAPHY OF SOUTHERN FLORIDA. 49 

might be expected, although a high beach ridge forms the backbone 
of Captiva Island. Between the mouth of the Caloosahatchee and 
Caximbas there are said to be two dunes, one on a small inner key 
near Estero, the other, much larger, on the mainland about halfway 
between Marco and Naples. 

South of Caximbas there are no dunes, not even back of the 10-mile 
stretch of sandy beach at Cape Sable, and there are none along the 
southern edge of the mainland from Cape Sable eastward. 

From this review it appears that though the distribution of the 
south Florida dunes is in some way related to the present coast line, 
the relation is not a definite one. The high ridges lie back fromi the 
ocean and from the Gulf, yet extend only a few miles inland. Those 
lying on keys rise out of mangrove swamps where dune building is 
now impossible; those near open water, like the dune back of Jupiter 
Light, generally lie back of a protecting key and back of a fringe of 
mangroves. 

ROLLING SAND PLAINS. 

By rolling sand plains is here meant sandy stretches of the main- 
land undulating in broad swales and low ridges. In the swales are 
shallow lakes or lagoons, wet prairies, or cypress swamps. On the 
east coast these sand plains form a belt that extends, with a maximum 
width of 6 miles, from the north side of Palm Beach County nearly 
to Miami Kiver. Out of this belt rise most of the dune mounds and 
ridges. Inland the rolling sand plains merge imperceptibly into the 
monotonous level of the flatlands and the prairies bordering the 
Everglades ; seaward they are bounded by swamps or by open water. 

On the west coast south of Caloosahatchee River the rolling sand 
plains are of relatively slight importance, though in them may be 
included the arable land, a succession of beach ridges back of the 
present shore line at Cape Sable, and the sandy keys, many of them 
not pine clad, that fringe the coast from Cape Romano northward. 

Near the shore on the east coast the higher ground and the ridges 
of the sand plains are in many places covered with a straggling 
growth of spruce pine. In the hollows are many fresh-water lakes, 
some several miles long. Most of these are less than 10 feet deep, 
and some are so shallow that they disappear entirely for months 
during a period of deficient rainfall such as prevailed from November, 
1906, to May, 1908. A few of the lakes may be over 10 feet deep, 
and the writer was told that Lake Osborne had a maximum depth 
at the end of a normal rainy season of 30 feet, extending some feet 
below sea level. However, the lakes, as a rule, are so shallow and 
the slopes of their banks so gentle that a survey of the rolling 
sand-plain country made in or shortly after a summer of normal 
rainfall would show vastly different relations of land and water from 



50 GEOLOGY AND GEOUND WATEKS OF ELOKIDA. 

one made in early spring following a year of deficient precipitation. 
This accounts in part for lakes appearing on maps of southern Florida 
at many places where the visitor may find none. 

The sand grains, like those of the dunes, are angular rather than 
rounded. They are gray at and near the surface, but become yel- 
lowish a short distance below, except in places where water stands 
during most of the year. The decoloration of the sands near the 
surface is to be explained by the decay of plant roots, the action of 
soil bacteria, and the leaching effect of rain. 

The character of the sands and the elevation and prevailing trend, 
parallel to the coast, of the ridges indicates that the rolling sand plains 
are in part beach deposits and in part the work of the wind and that 
they are related to the dunes. 

FLATLANDS. 

The term ^^flatlands" is applied to the imperfectly drained pinelands 
lying between the rolling sand plains and the Everglades or their 
bordering prairies and forming a discontinuous strip of country 
which on the east coast extends from the north side of Palm Beach 
County to the vicinity of New River, in Dade County. Its greatest 
width back of Hobe Sound is about 10 miles. 

The flatlands have a soil of light-gray sand, resembling that of the 
rolling sand plains, and bear a thin growth of pine trees separated in 
places by expanses of prairie a mile or more wide, a difference of a 
foot in elevation determining the character of the vegetation. In 
the rainy season these prairies are shallow lakes. In the flatlands 
lie also exceptional sloughs or pond holes, some of which are a fourth 
of a mile or more across, and which, being 3 to 5 feet below the 
general level of the countiy, are never entirely dry. In places these 
deeper hollows support good growths of cypress, and as the region 
of relativel}^ permanent standing water, the Everglades, is approached 
the pine and the cypress growths intermingle in most irregular 
fashion. In some places pines grow up to the edge of the prairie 
bordering the Everglades ; in others a fringe of dwarf cypress separates 
pineland and swamp; and in still others considerable areas sup- 
port good growths of cypress. 

On the west coast the surface of the country between the Everglades 
and the Gulf is even more monotonously level than that of the east 
coast and the relations of swamp and dry land are more irregular. 
Much of the pine grows in patches and strips, in places miles in 
extent, separated by cypress swamps. In consequence, the timber- 
clad flatlands of the west coast are described as pine islands and 
cypress strands. Prairies are scattered through or fringe the pine- 
lands, and toward the Everglades and north of the Big Cypress great 
stretches of prairie make excellent cattle ranges. 



GEOGRAPHY OF SOUTHERN FLORIDA. 51 

ROCK RIDGES. 

The absence of rock outcrops over the greater part of that portion 
of the mainland included under the term southern Florida is strikmg, 
and indeed remarkable when one finds that in many places solid 
rock lies only a few feet below surface. To outcrops of any extent 
the term rock ridges is here applied, though it should be understood 
that these rock ridges may not rise more than 2 feet above the level 
of the surrounding country and probably nowhere have an elevation 
exceeding 25 feet above sea level. 

The rock ridges of the east coast comprise the prominent outcrops 
of oolitic limestone that extend from 5 miles north of Miami to 
Homestead and separate the great saw-grass swamp of the Everglades 
from the fringe of mangrove swamps and salt prairie along the western 
shore of Biscayne Bay. This rocky country forms part of the Bis- 
cayne pineland. The area of these outcrops is estimated at 200 
square miles, but is really a matter of conjecture. The relations of 
rock ridge and prairie along the western edge of the pineland are 
extremely intricate, the elevation of the outcrops falling gradually 
to the level of the Everglades and the pineland tapering off in a series 
of rocky keys or islands (of which Long Key is the largest) that extend 
fully 15 miles beyond the southwest corner of the main body of the 
pineland. Over many square miles between Miami and Long Key 
and about Long Key the limestone forms the surface. North of 
Miami the outcrops are mantled by sand before the elevation of the 
rock surface has become as low as 6 feet above mean sea level. 

North of New River, between the sea and the Everglades, except 
for the coquina near the beaches, outcrops of rock are few and scat- 
tered. In the Everglades some of the keys have a rocky foundation, 
such being reported nearly to Lake Okechobee, but so far as known 
the only ones that form bare rock ridges are Long Key and the keys 
related to it, none of which reach as far north as the latitude of 
Miami. 

On the west coast of southern Florida hard rock outcrops are more 
scattered than on the east but cover a much wider area. Throughout 
the pine island and cypress strands, limestone projects here and 
there through the sands and is found along the roads from Fort Myers 
to Fort Shackelford and from Fort Myers past Immokalee to the head 
of Aliens River. Moreover, narrow interrupted strips of bare rock, 
some of them several miles in width, run through the pinelands. 

A peculiar feature of the rock outcrops of southern Florida is the 
erosion of the surface. On the west coast, where the limestones are 
denser and finer than on the east coast, the rocks weather irregularly 
into rounded knobs and lumps a few inches to a foot above the general 
level of the surrounding sands, making it difficult to drive a wagon 



52 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

across bare expanses. In the rocky area of the east coast the softer 
ooHtic limestone weathers into angular shapes, producing extremely 
rough surfaces and making walking a task that requires constant 
watchfulness. The ground is strewn with loose, sharply angular 
fragments (products of weathering and of the disruptive power of 
tree roots), and fixed angular masses a foot or so high, with irregularly 
pointed summits and jagged outlines, vaguely suggest miniature 
pagodas. 

Hand in hand with this surficial erosion has gone underground 
solution. Next to the bristling rock surface, the most striking feature 
of the Biscayne pineland south of Miami is the presence of innumer- 
able holes and hollows. The holes, which communicate with under- 
ground solution channels, are of all sizes, varying from not over an 
inch across to 20 feet or more in diameter. Besides the sharply out- 
lined holes, there are throughout the pineland countless shallow hol- 
lows 1 to 3 feet deep and 10 to 100 feet across. A few of these hollows 
owe their origin to original conditions of deposition, some may be due 
to the overturning of trees and consequent upheaval of the rocks by 
roots, and others have been caused by the falling in of the roofs of 
subterranean watercourses. 

Few of these holes and hollows are large enough to be termed sinks. 
The large vertical-walled holes running down to permanent water 
level form natural wells; the shallow hollows are best denominated 
potholes. Deep, or Devils, Lake, near the west coast, 12 miles north 
of Everglade post office, is, so far as the author knows, the only rock- 
rimmed opening in southern Florida that resembles the great sinks 
in the country to the north. It is about 500 feet across, is nearly 
circular in outline, and its reported greatest depth is 90 feet. 

Although there is danger of exaggerating the activity of under- 
ground and surface water in eating away the soft limestone of the east 
coast, yet there are plentiful evidences of solution. The potholes 
and the hoUow-sounding areas of rock, perhaps 25 feet across, with 
as many as six or seven holes a foot or so in diameter showing the 
water beneath, that are found along the edges of the southern Ever- 
glades; the springs below tide level at Cocoanut Grove and other 
points on the shore of Biscayne Bay; the Punch Bowl, a spring basin; 
the deep holes in New River; and the shallow gorge of Arch Creek, 
with its low rock bridge — aU bear witness to the work that is being 
done. 

SWAMPS. 
CONTROLLING CONDITIONS. 

As before stated, the swamp land of southern Florida includes the 
great saw-grass morass of the Everglades, the cypress swamps and 
strands around its edges or intermingled with the pineland, and the 
salt meadows and mangrove swamps of the coast. The very slight 



GEOGRAPHY OF SOUTHERN FLORIDA. 53 

differences in elevation over long stretches of the mainland, the 
gradual slope of the rock surface below sea level, the rock ridges on 
the southeast, the configuration of the upper surface of the bedrock, 
and the rapid growth of grasses and sedges are all factors in the 
distribution of land that is permanently wet and of that which is, 
for a part of every year, dry. 

EVERGLADES. 

Extent. — It is difficult for a person who has not seen the Everglades 
to form even an approximate idea of that far-extending expanse of 
sedge, with its stretches of shallow water, its narrow winding channels 
of deeper water, its scattered clumps of bushes, and its many islands. 
Photographs fail to convey the impressions of distance, of remoteness, 
and of virgin wildness which strike the visitor who for 1?he first time 
looks out across that vast expanse. 

The Everglades occupy the greater portion of southern Florida. 
They reach from Lake Okechobee on the north to the vicinity of 
Whitewater Bay on the south and may have a maximum width of 
60 miles. They have not been surveyed and their exact area is 
undetermined, but it is estimated at 5,000 square miles. The relief 
of the drier land is slight and the actual dividing line between saw- 
grass morass and cypress swamp, prairie, pineland, and coastal 
swamp is extremely intricate. A difference of 2 feet in water level 
means the difference between shallow lake and dry land over hundreds 
of square miles. Hence, the relation between land and water shown 
on a particular map is not necessarily to be taken as absolute or 
even general; it may only show the relation as determined in the 
month or months and year of the survey. 

On the north the main body of the Everglades reaches to the south- 
ern and southwestern sides of Lake Okechobee. Arms extend 
farther north, but much of the eastern and most of the northern 
shore of the lake is bordered by cypress swamps, some of these con- 
taining the tallest and cleanest cypress to be found in Florida. 

East of the lake the Everglades fade away irregularly in the Alla- 
pattah Flats, a region largely under water at the end of each rainy 
season, where interwinding strips of saw-grass swamp and grassy 
prairie, set with patches of cypress and, more rarely, with hammocks 
of hardwood, stretch away in an almost dead level. Farther south 
the Everglades are bordered by prairie and cypress swamp or at a 
few places reach nearly to the coast. The rocky pine-clad islands 
that extend southwestward from the main body of the Biscayne pine- 
land nearly to Whitewater Bay have a fringe of prairie, but east of 
them lies a saw-grass strait and to the south lie wide expanses of saw 
grass dotted with keys that disappear seaward among thickets of 
dwarf cypress or mangrove. On the west the Everglades from 



54 GEOLOGY AND GROUND WATERS OF FLORIDA. 

Whitewater Bay to Lostinans River reach the mangrove swamps that 
fringe the coast. North of Lostmans River an arm of the Ever- 
glades runs up between the mangrove swamp and the prairie border- 
ing the pine islands and gradually disappears before reaching Aliens 
River. Cypress swamp and prairie form the western boundary of the 
main body of the Everglades from Lostmans River to Caloosahatchee 
River. A narrow strip of small cypress is said to extend along the 
western edge of the Everglades for 60 miles south of Sam Jones town. 

Elevation and drainage. — Differences in elevation are slight; few 
of the islands are more than 2 feet above high- water level, and the 
slopes are so gentle as to be detected only by the movement of the 
water or by leveling. The general slope is south but, in spite of the 
water seen everywhere in the rainy season, is not uniform. Low, 
irregular rises, measured by inches only, serve to diversify the water 
and sedge-covered peat in the dry months of the year. There are 
also sloughs — narrow \\'inding strips of open water through the sedge — 
some of wliich extend for mUes. Often it is not possible to detect 
a persistent current in these passages, which, for the most part, 
seem to lie north and south along the west side of the Everglades and 
north-northwest and south-southeast along the east side. 

The water brought down by Kissimmee River escapes from Lake 
Okochoboo through a canal connecting with the Caloosahatchee and 
through the saw grass. The short streams around the southern edge 
of the lake, shown on most maps of Florida, do not flow into the lake 
but from it. They close up within a few miles and the thick growth 
of saw grass makes the movement of water in any given direction 
very slow. Some of the water entering the lake reaches the Gulf 
and some the Atlantic, the water moving as a mass slowly south- 
ward. When the lake rises to about 22 feet above mean sea level 
it is said to overflow into the Everglades along its whole southern 
border. 

As e^'idence of the flatness of the Everglades, residents of the east 
coast state that when the canal leading from the lake was dammed 
at Lake Hicpochee in the year 1904, raising the level of the water 
above the dam 3 feet, more water came down the east coast rivers 
as far south as New River, and the marginal prairies were under 
water so late in the fall as to hinder seriously the ofrowino: of 
vegetables, but whether the dam caused all the trouble complained 
of is doubtful. 

Since Lake Okechobee overflows to the south and the waters escap- 
ing from it may reach either the Atlantic or the Gulf, the elevation of 
its surface is in a way a measiu-e of the elevation of the Everglades. 
Several determinations of its level have been made by Government 
engineers and surveyors. An elevation of 20.4 feet was found by a 
party of engineers in April, 1901, but an even lower level — 19.8 feet — 



GEOGRAPHY OF SOUTHERN FLORIDA. 65 

is reported to have been found in March, 1908. High-water levels 
pubHshed by the United States Chief of Engineers are 22.4 feet in 
1886 and 23.4 feet in 1878. Comparatively few determinations 
along the edges have been reported. Some detemiinations along the 
eastern margin are: West of Lantana, 18 feet; west of Hillsboro Inlet, 
14 feet; west of Fort Lauderdale, 3 to 9 feet; at the pool at the 
head of Miami Eiver, 6.2 feet. South of the Biscayne pm eland and 
Long Key the height of the Everglades is less than 6 feet. Wright ^ 
says that the mean water level of the lake is 20.5 feet, that the low- 
water level is about 19 feet, and the greatest depth at low water is 
22 feet, making the bottom at that point 3 feet below sea level. 

Willoughby in his trip across the Everglades from Harney River 
to Miami River found that the water on the west side had a slow move- 
ment southwest, and on the east side a similar movement southeast. 
Ingraham, who crossed the Everglades from Fort Shackelford to 
Miami, found a southerly movement in a creek connecting Okaloa- 
koochee Slough and the Big Cypress but little current in the sloughs. 

W. J. Krome, who made a careful survey of the southern Everglades 
for the Florida East Coast Railway, found a slight southerly current 
in the slough that forms the headwaters of Taylor River between the 
mainland and Long Key. The writer, however, found no perceptible 
current in this slough near Paradise Key in June, 1908. 

Evidently at times of high water there is a perceptible movement 
of the water of the Everglades down the slight slopes toward the 
nearest outlets. At times of extremely low water the sloughs may 
be so separated that except in the immediate vicinity of a river no 
current is perceptible. 

The normal difference between high and low water in the Ever- 
glades is about 2 feet ; the maximum difference may be twice as great. 
In the spring of 1908 it was possible to travel by wagon from the 
Biscayne pineland to and about Long Key, whereas in the early 
winter of 1906-7 one could cross the southern Everglades in a power 
boat. During the Seminole War successful pursuit of the Indians 
depended on a depth of water sufficient to permit the use of ship's 
boats. 

Bedrock. — The Everglades have been variously caUed a lake in a 
rock-rimmed basin and a vast sink. In the Light of the facts accu- 
mulated by surveys of the War Department, the Disston Co., the 
Florida East Coast Railway, and the State of Florida, and by the 
explorations of Ingraham, Willoughby, and others, both these desig- 
nations appear inexact. 

Bedrock apparently lies at or near the surface around the edges 
of the Everglades. Along the east side from Jupiter River to HiUsboro 

1 Wright, J. O., Report of the special joint committee of the legislature of Florida on the Everglades 
of Florida, p. 5, 1909. 



56 GEOLOGY AND GKOUND WATERS OF FLORIDA. 

River outcrops are few. South of New River they are more numerous, 
and from just north of Miami to Homestead the rock forms bare 
ridges with a maximum elevation of 15 feet above mean water level 
in the Everglades. This line of ridges bends at its southern end to 
the west and gradually disappears as a series of rocky keys runniag 
west and southwest and reaching nearly to Whitewater Bay. South 
of this rock ridge, from Cutler on Biscayne Bay around the southern 
end of the mainland, past Cape Sable, Whitewater Bay, Ponce de 
Leon Bay, and the Ten Thousand Islands, there are no outcrops of 
bedrock above the sea level; nor are there any along the shore south 
of Sanibel Island. On the southwestern side of the Everglades rock 
comes within a foot of low-water level in Rock Creek, an arm of one of 
the series of bays that together make up much of the lower 12 miles of 
Lostmans River. Three miles northeast of this point rock outcrops 
in a pine island. Thence northward many rock exposures are scat- 
tered through the flatlands. They can be seen at the head of Aliens 
River and 11 miles to the east on the property of the Deep Lake 
Fruit Co. The belt of country in which rock is exposed widens north- 
ward and at Naples is fully 40 miles wide from east to west. This 
region is monotonously level and the rise of the rock surface inland is 
shght. In short, bedrock outcrops around the main body of the 
Everglades from Jupiter River to Fort Shackelford with no important 
interruption except between Lostmans River and the westernmost 
of the rocky keys beyond Long Key. In this break rock does not on 
the average lie more than 5 feet below the level of low water. 

If allowance be made for the general slope of the water level toward 
the drainage channels on the east and west coasts, the hydrauUc 
gradient amounts to 0.3 foot per mile for 30 miles northwest of Miami. 
It is evident that the actual depth to bedrock in the middle of the 
Everglades is only 3 to 4 feet below a level line extending from rock 
rim to rock rim. As these points might be 40 miles apart, and as 
the depth below the line at the latitude of Miami averages less than 
5 feet, the inappropriateness of the term basin for the southern por- 
tion of the Everglades is evident. 

Nor is the term sink more accurate. The area is too large ; the rock 
floor too flat. Potholes and small sinks are common in the rocky 
prairie south and southeast of the main body of the Everglades, and 
large sinks filled with mud may exist in the main expanse, but their 
existence is not proved. Possibly, also, sinks of some size may exist 
between the liae of rocky keys and the north shore of the Bay of 
Florida. Certain features of Bear and other lakes back of Flamingo 
suggest that they are sinks. 

Although the rock floor of the southern Everglades is known to be 
almost flat, yet it is altogether possible that farther north there are 
true basiQs of considerable extent. The preliminary surveys for the 



GEOGRAPHY OF SOUTHERN FLORIDA. 57 

drainage work undertaken by the State at New River showed that 
bedrock sloped off more steeply at that place than to the south or 
the north, and a depth of 20 feet to bedrock is probable in a strip a 
few miles widfe. Reports are current of an east-west rock ridge 
8 or 10 miles south of Lake Okechobee within 6 feet of the surface 
but are probably without substantial basis. A rock ridge rises 
north from Long Key, reaching as far north as Miami, but according 
to report, sounding with a lO-foot pole on a line from Fort Shackelford 
to Miami, found no rock till within 15 miles of Miami. Hence there 
is a probability that the Everglades cover a series of shallow rock 
hollows. Whether these hollows were as deep when first occupied 
by the Everglades as they are now, whether they represent original 
inequalities of deposition of the lime rock, or whether they are 
buried shallow valleys can not be determined from the evidence at 
hand. It is probable, however, that the deepening and enlarging 
effect of underground solution has been exaggerated. 

Bedrock lies 10 feet below low- tide level at Jewfish Qreek, 18 feet 
below at Flamingo, 5 to 10 feet below in Whitewater Bay, 13 feet 
below at the mouth of Shark River, 13 feet below at the mouth of 
Lostmans River, 12 feet below on Chokoloskee Island, and 5 to 10 
feet below at Everglade. 

Dredging in the canals west of Fort Lauderdale show rock (not 
oolite) near the surface 7 to 10 miles west of the town. Regarding 
the rock ridge reported in the Everglades south of Lake Okechobee, 
R. E. Rose, State chemist, who is familiar with the results of the 
Disston surveys, in a letter to the writer says that no rock was 
found at 12 feet, the length of the sounding rod, between a point 20 
miles south of the lake and the lake, and that he has never found rock 
with a 10-foot rod near the south side of the lake. According to 
his recollection, rock was found at 8 feet 20 miles south of the lake. 
The South Canal survey approaches the rock reef on the west (in 
T. 48 S., R. 35 E.); farther east the muck is deeper. 

The sHght westward slope of the larger part of southern Florida, 
to which reference has been made, is due to a recent tilting and to 
deeper accumulation of sand along the ocean than along the Gulf 
shore rather than to variations in bedrock level. The latter is 
effective only along the southeast side of the Everglades. 

Origin of the Everglades. — The Everglades owe their existence 
primarily to an abundant rainfall and to the slight elevation of 
southern Florida. Even were there no basin-like structure whatever, 
and were the bedrock surface absolutely flat along an east-west line, 
the present rainfall, the sluggish drainage, and the luxuriant growth 
of vegetation would result in a swamp forming across the center 
of the peninsula from Lake Okechobee. In short, the Everglades 
resemble in origin the Dismal Swamp of North Carolina and Virginia. 



58 



GEOLOGY AKD GEOUND WATEES OF FLORIDA. 



The peat found throughout a large part of the Everglades rests on 
rock, sand, or marl. In places soundings indicate more than one 
peat bed, with sand between. The relations of peat and sand to 
bedrock west of Fort Lauderdale are shown by a section along the 
drainage canal there. (See fig. 1 .) 



CYPRESS SWAMPS. 



Most of the many tracts of cypress scattered over southern Florida 
call for no especial notice. Probably the finest cypress grows north- 
east of Lake Okechobee, but the largest tracts of good timber are 
west of the Everglades; Okaloacoochee Slough and the Big Cypress 
are the two most important. Both have extremely irregular outlines 
with numerous arms forming strands among adjacent pine islands or 
prairies. The southern boundary of the Big Cypress is not indicated 
on most maps of southern Florida and on many its extent is greatly 
exaggerated, the name being printed across a region where cypress 
swamps, prairies, hammocks, and pineland are intermingled. During 



A-- 




Sand 



Limestone 
(Miami oolite) 



Figure 1. — Section near edge of Everglades west of Fort Lauderdale. A-B, sea level. 
Vertical scale, 1 inch = 36 feet; horizontal scale, 1 inch = If miles. 

periods of high water boats can pass through the Big Cypress from 
the Everglades to the Gulf north of Cape Eomano. The maximum 
east-west width of the swamp may be 40 miles. Ten miles east of the 
head of Henderson Creek is a cypress swamp 6 miles wide, and east 
of Everglade is another swamp 6 to 12 miles wide, these swamps 
being connected with other swamps that form arms of the Big 
Cypress. 



COASTAL SWAMPS. 



As a consequence of the low relief and the gradual slope of the 
land below sea level, southern Florida has wide areas of coastal 
swamp. These areas include (1) wet lands along lagoons or rivers 
lying back of the barrier beaches of the east coast, covered partly by 
open marsh and partly by scrubby growths of mangrove, and (2) the 
more extensive swamps of the south and southwest coast, which die 
away in a network of channels and islands. On the west coast 
these mangrove-covered islands and the mangrove swamps behind 
them extend from Whitewater Bay, the southernmost arm of which 
is separated from the Bay of Florida by less than 5 miles of wet 
prairie and swamp, to Cape B-omano. North of Marco the coastal 



GEOGRAPHY OF SOUTHERN FLORIDA. 59 

islands and the swamp land include pine islands, and in places north 
of Naples pines grow to the Gulf shore. 

The red mangrove most frequently grows as a bushy tree, under 20 
feet high. The swamp that forms the southern fringe of the main- 
land from Chis Cut to 6 miles east of Flamingo has such low trees, 
as have many islands in Whitewater Bay and most of the patches of 
swamp along the main line of the Florida Keys from Biscayne Bay to 
the Marquesas. But in the Shark River archipelago and the southern 
portion of that unmapped maze of land and water, the Ten Thousand 
Islajids, the mangrove forms a noble forest, the trees growing to a 
height of 60 feet or over with clean smooth trunks 2 feet or more in 
diameter at the butt and without a limb for 30 feet from the ground. 
They rise from the Gulf like a green wall and are one of the most 
striking features of the shore line of southern Florida. The majestic 
appearance of these trees compared with the look of those in White- 
water Bay can not be explained by any local peculiarity of climate. 
Rather does it result from the aeration of the thick bed of soft gray 
marl on which they grow by the swing of the tides, which here have 
greater amplitude than anywhere else on the whole coast of the 
peninsula, fully 5 feet. Northward, toward Cape Romano, the trees 
become smaller and along the inlets back of Caximbas they are as 
bushy as in Whitewater Bay. 

The maximum width of coastal swamp in southern Florida is un- 
known, since the boundary between coastal swamp and Everglades 
is a matter of conjecture. After a season of heavy rainfall the chan- 
nels leading from the latter carry fresh water and after a dry season 
salt water. Thus in May, 1908, the writer found salt water in Lost- 
mans River within the Everglades, 17 miles from the mouth of the 
river, while in October of the same year, after the heavy rainfall of 
the summer and early fall, the water was fresh to a point within 5 
miles of the Gulf. 

THE KEYS. 

GENERAL CHARACTER. 

The keys or islands that fringe the south Florida mainland differ 
greatly in size, shape, and surface features. Some are typical barrier 
beaches, long, narrow, low-lying banks of sand, crowned with coco- 
nut palms and buried in mangrove swamps to landward. Many are 
true mangrove islands, shoals formed by the efforts of tidal and wind- 
induced currents where mangroves were able to take root and arrest 
material thrown up by the waves. Others are sand banks so low- 
lying or so exposed as to support only a scanty growth of beach 
grasses and weeds; and still others, notably those in the main chain 
that extends from Virginia Key opposite Miami to Key West, are of 
rock or have a rock foundation reaching to or above mean sea level 



60 GEOLOGY AND GKOUND WATEKS OF FLORIDA. 

and covered with various scrubby hardwood trees, palms, and even 
pines. 

Within this chain, fringing the mainland or dotted over the Bay of 
Florida are many keys in all stages of growth, from banks below sea 
level to banks just bare at low tide on which mangroves have got a 
foothold and by their entangling roots are catching seaweed and drift- 
wood, arresting the movement of calcareous sand and mud, and ac- 
tively pushing out the shore line. Whitewater Bay, which lies behind 
Cape Sable and has an extreme northwest-southeast length of perhaps 
20 miles, is full of these mangrove islands. 

North of Whitewater Bay the Ten Thousand Islands form a 
network of channels and of marl banks supporting a heavy growth of 
red and black mangrove. From Big Marco Pass to Sanibel Island an 
almost continuous beach of siliceous sand, broken only by narrow 
inlets, such as Johns Pass, Gordon Pass, Big Hickory Pass, and Big 
Carlos Pass, faces the Gulf. These passes lead to inner "bays " dotted 
with islands of many sizes, but with few features of especial interest. 

Though the islands along the coast of southern Florida may be 
readily divided into definite types, as barrier beaches, rocky islands, 
and mangrove islands, it is not possible to state from present infor- 
mation the relative importance of these types. 

The decided differences of surface of the keys — bare rock or rock 
with a very thin veneer of leaf mold, sand, and marl — and the slight 
differences of elevation above high tide, have resulted in great differ- 
ences of vegetation. 

Near the water's edge and on flats or on rock beaches below high- 
tide level grow mangroves; on the beach ridges coconut palms, not 
indigenous, flourish. Inland the low marl flats support grasses, 
sedges, and salt meadow weeds. The higher ground, called hammock, 
supports a dense growth of scrubby hardwood trees, buttonwood, 
ironwood, and madeira, little of which attains a height of more than 
20 feet. Three of the keys. No Name, Little Pine, and Big Pine, 
notably the latter, carry patches of pine. 

The rock outcrops along the keys differ from those of most of the 
bare rock in the Biscayne pineland or in the flat lands of the west 
coast between the Everglades and Cape Romano. They are less 
weathered, hence more even, and not jagged looking, except on spray- 
worn beach slopes. Angular blocks, disrupted by tree roots or by 
temperature changes, are scattered over them, but in places the sur- 
face is comparatively smooth over areas of 20 to 100 square yards. 
Holes and hollows resembling those found in the Biscayne pineland 
and formed in the same way abound, but the rock itself has a look 
of newness ; its major inequalities are not the result of subaerial decay. 
It is like that of some of the low keys in the Everglades west of Long 
Key. 



GEOGRAPHY OF SOUTHERN FLORIDA. 61 

Since the keys were elevated to their present height they have 
been subjected to forces that tend to advance the shore line and to 
those that tend to push it back. The easterly winds have played an 
important part in giving the eastern and southern faces of the keys 
their present forms. Differences in time and height of tides in Florida 
Strait and the Bay of Florida, together with the area of the bay, result 
in strong currents sweeping through the passages between the keys, 
particularly the openings west of Long Key. When northers blow 
the shallow waters of the bay are milk-white over large areas from 
the limy stuff in suspension. This is deposited, to be picked up with 
a change of wind or tide, or is carried to sea in such quantities as to 
show in the blue waters of the Gulf Stream 10 miles outside the keys. 
The bars and banks about the keys and in the Bay of Florida, the 
areas of marl and calcareous sand above sea level, show the activity 
of waves and currents and indicate how much material they have 
recently handled. 

THE FLORIDA REEF. 

The shores of the main line of keys, extending from opposite Bis- 
cayne Bay to Key West and Boca Grande, are in places rocky and 
in other places are bordered by flats of soft marl or calcareous sand. 
On some keys the surface is bare rock; on others it is sand or marl; 
on very few do wide strips of land stand as much as 6 feet above the 
highest spring tides. (See PI. VII, A, B.) 

The longest key — Key Largo — is 30 miles in extreme length, but is 
nowhere over 3 miles wide, and its maximum width above the high 
spring tides is considerably less. Big Pine Key is 10 miles long and 
its high ground is nearly 2 miles wide with a greatest elevation of 10 
feet. Key West is 4 miles long by 1 mile wide and its highest ground, 
which is near the center of the city of Key West, has an elevation of 
13 feet. The highest measured points in the whole chain of keys are 
two small knolls 18 feet high, one on Windleys Island and the other 
on Plantation Key, just to the north. The knoll on Windleys Island 
was quarried for fills and ballast along the railway line to Knights 
Key. 

The Florida Keys are separated by Bahia Honda Channel into two 
distinctly differentiated divisions. East of the channel the islands 
are narrow and lie along a sweeping arc curved toward the southeast. 
Outside this arc is the Florida Strait; inside it are the Bay of 
Florida, Barnes Sound, Blackwater Bay, Card Sound, and Biscayne 
Bay, The western end at Bahia Honda is 35 miles from East Cape 
on Cape Sable, the nearest point of the Florida mainland. The rock 
ridge of Key Largo is not 2 miles from the edge of the mangrove 
swamp that fringes the end of the peninsula and from there northward 
the keys are within 8 miles of the mainland. 



62 GEOLOGY AND GKOUND WATERS OF FLORIDA. 

West of Bahia Honda the keys form an archipelago roughly trian- 
gular in outline. In this group, the westward prolongation of the 
arc in which lie Bahia Honda and the keys to the east and northeast 
is found in the southern shore line of the keys ; but the keys themselves, 
instead of lying parallel to this arc, have a prevailing north-northwest, 
south-southeast arrangement, perpendicular to the arc. The causes 
of this striking dissimilarity in position are twofold, a difference in 
rock structure and a difference in the direction of the forces which 
have shaped the islands. 

Bahia Honda and the keys east of it represent an uplifted coral reef 
more or less covered with sand and marl ; hence their basement rock 
ridges have the trend of the coral patches of the old reef. The keys 
west of Bahia Honda consist of an oolitic limestone formed from depos- 
its in a broad expanse of shallow water; hence there was no original 
ridgelike upbuilding, no pronounced trend to the rock structure. Dif- 
ferences in resistance to erosion have resulted in irregularities of the 
rock surface, which, as along the old reef to the east, have been more 
or less covered with marl and calcareous sand. The prevailing north- 
south trend of the passages separating the keys, hence the trend of the 
keys themselves, is due to tidal currents, which owe their power to 
differences in time and height of the tides of the Gulf and the Strait 
of Florida. 

The shaping of the great arc of the keys is the joint production of 
several factors. The old coral reef that forms its greater part was 
built up from the bottom in water of a certain depth along a line that 
had the general direction of the southeastern and southern edge of 
the submarine plateau of the Florida peninsula. The curve of its 
western end was controlled more or less by the eastward flow of the 
Gulf Stream against the westerly movement of the prevailing winds. 

The writer did not visit the Tortugas, which have been described 

by Agassiz and by Vaughan, nor the Marquesas, an atoll-like group 

of beach ridges and mangrove islands that is presumably underlain 

by the Key West oolite not more than 10 to 15 feet below sea level. 

The Marquesas are of Recent age, and according to Vaughan the 

Tortugas are also. 

THE SHORE LINE. 

TOPOGRAPHY. 

The shaping of the shore lines of any region is the joint work of 
tidal and wind-made currents, waves, and winds. The share of each 
of these agencies is determined by the efficiency permitted through 
antecedent conditions of coastal topography, the character of the 
shore-line materials, and the circumstances controlling the general 
circulation of ocean currents and winds, and the work being done at 
any given time is in a measure controlled by the rise or fall of the 
land with reference to sea level. Thus shore-line features have the 
aspects of infancy, adolescence, or maturity, according to the length 



U. S. GEOLOGICAL SURVEY 



WATER-SUPPLY PAPER 319 PLATE VII 




A. BEACH RIDGE OF CORAL AND SHELL SAND, KNIGHTS KEY. 




B. CALCAREOUS SAND ON REEF ROCK. 



U. S. GEOLOGICAL SURVEY 



WATER-SUPPLY PAPER 319 PLATE VIII 




A. MANGROVE KEY, WATER'S EDGE. 




B. ROOT GROWTH OF MANGROVES, SOUTH END OF KEY VACA. 



GEOGEAPHY OF SOUTHEEIT FLORIDA. 63 

of time the waves and currents have been working at a certahi level 
and the eJffectiveness of their attack on the land. In the same region, 
as in southern Florida, adolescent features may be found where the 
attack is strong, and infantile where the attack is weak or ineffective. 

The south Florida mainland is low, its coasts dip gently beneath 
the water, and the shore-line materials are nearly everywhere uncon- 
solidated. Under these conditions slight changes of level can swing 
shore lines over long distances, and the effectiveness of wave attack 
is easily modified by agencies, such as corals, which tend to build up 
land, or agencies, such as mangroves, which tend to push out the 
shore. (See PI. VIII, A, B.) 

The region has no well-marked valleys and no large rivers; hence 
antecedent drainage has been of minor importance in determining 
the work of waves and currents. The streams are clear, they bring 
down little matter in suspension, their waters are not heavily miner- 
alized, and they contribute comparatively little to the sea bottom; 
hence delta building is insignificant. At the same time an immense 
amount of limy material is supplied by the remains of marine organ- 
isms, the agitation of the shallow near-shore water facilitates the depo- 
sition of calcium carbonate, and the efl3.uent swamp waters contain 
organic compounds that may act as precipitants; hence banks of 
marl form near river entrances or outside of passages leading from 
lagoons, and where the banks are protected mangroves gain a foot- 
hold and interrupt the sequence of forms that would result from the 
unopposed action of waves and currents. 

Maps of the east coast show a shore line with adolescent features, 
such as cuspate forelands, well-developed bay bars, and long beaches 
with gentle curves. The offsets and overlaps of the bars and beaches 
show that the movement of sand is toward the south. This move- 
ment is very marked at Jupiter Inlet. When the bay bar at the 
mouth of the inlet is cut through at its north end to make a navigable 
channel, the drift of the sands makes the channel travel southward, 
till as it approaches the south side of the inlet it shoals up and the 
water flows over the bar in a shallow sheet. 

OCEAN CURRENTS. 

Vaughan has summarized the action of the forces that produced 
the Floridian Plateau and has called special attention to the impor- 
tance of ocean currents, as follows: ^ 

The importance of currents in shaping the land area of Florida has been emphasized 
in several sections of the preceding discussion. Before the history of the currents of 
the region can be thoroughly understood it is necessary to know the history of the Hat- 
teras axis of North Carolina. The present Florida countercurrent seems due partly to 
the impingement of the Gulf Stream against the Hatteras projection, resulting in a 

1 A contribution to the history of the Floridian Plateau: Pub. Carnegie Inst. Washington No. 133, 1910, 
p. 18o. 

76854°— wsF 319—13 5 



• 64 GEOLOGY AND GEOUND WATERS OF FLORIDA, 

portion of the waters being deflected southward along the coast instead of continuing 
their northward journey. The Hatteras axis has existed as a dividing line between 
depositional areas apparently since Middle Cretaceous time, and it has been either a 
region of shoal water, or occasionally a land area, since later Eocene time. The Vicks- 
burgian and Apalachicolan seas were both warm, tropical or subtropical in tempera- 
ture. It is not definitely determinable at present whether the warmth of these waters 
was due to currents directly from the Tropics or to warm return currents produced by 
the northward-flowing Gulf Stream having a portion of its waters diverted southward 
by impinging against a salient from the more northerly land area. 

In Miocene time it is definitely known that a cold inshore current found its way 
southward to Florida and westward to Pensacola. This current may be due to the 
Miocene submergence of the Hatteras area sufiiciently lowering the sea bottom off Hat- 
teras to permit the Gulf Stream to continue its course unobstructedly northward. 
Should this hypothesis be correct a reexamination of the faunas of the Miocene depos- 
its of northern North Carolina and Virginia, and those of southern North Carolina (the 
Duplin marl), South Carolina, Georgia, and Florida, with reference to synchrony 
may be necessitated. The Miocene southward current transported quantities of ter- 
rigenous material and deposited it on the eastern border of the Floridian Plateau. 

Since Miocene time there have been constantly return currents of warm water (how- 
ever, not 80 warm as the Gulf Stream), and they, aided by winds and tides, have 
deposited terrigenous material on the eastward side of the existing land areas, sweep- 
ing a portion of it to the southern end of the Plateau. These currents were active 
during Pliocene and Pleistocene times, and are still active to-day. 

The shape of the upper surface of the Floridian Plateau, the land area of its eastern 
side, the arrangement of the geologic formations of successive ages, the directions of 
the stream courses, and the contour of the present coast line owe their peculiarities 
and characteristics to the concomitant operation of the forces producing deformation 
and to oceanic currents. 

The writer does not share Vaughan's view as to the existence of 
great return eddies of the Gulf Stream and their effectiveness in 
modifying coast lines, either to-day or in time long past. The sand 
grains along the east coast of Florida have traveled southward not 
at great depths but in shallow water, along beaches and bars. Such 
being the case, their travel was determined by the inshore waves 
and currents, which are mostly tidal or wind induced. The angle 
of incidence of the waves along a stretch of beach is chiefly a matter 
of wind direction. Were the near-shore currents and waves to move 
material northward rather than southward, a return eddy of the Gulf 
Stream, a mile or more offshore, would have very little to do with 
the shaping of the shore line. Moreover, the writer doubts the 
existence of a great eddy of the form that Vaughan's words imply. 
Of course, the movement of such a body of water as sweeps through 
Florida Strait must be accompanied by eddying, but the writer in 
his observations along the keys saw no sign of any general, persistent 
return eddy. The drift of sand and mud, as indicated by beaches, 
banks, and bars along the great arc of the main line of the keys, is 
the work of local inshore currents that change continually in direc- 
tion and strength but are chiefly controlled by the tides and the 
more effective winds. A balance of effect is shown in the Marquesas, 
where waves from the east and waves from the west seem to be of 
nearly equal strength in piling up sand and mud. 



PART II.— GEOLOGY. 
NORTHERN AND CENTRAL FLORIDA. 

By G. C. Matson. 
GEOLOGIC RECORD. 

The processes which formed the rocks comprising the State of 
Florida have changed from time to time, but they have always 
3een similar to those now operating along the coast. That the 
'ocks are largely of marine origin is shown by the presence in 
nany of them of shells of marine animals similar to those that live 
ilong the coast to-day. When the sea was clear animal life abounded 
md the shells accumulated to form limestones, but when the water 
yas muddy sand and clay predominated in the deposits. Thus the 
'ocks of Florida record the conditions which existed during their 
ieposition. In some places accumulations of clay, sand, and gravel 
ippear to have taken place on land or in rivers and lakes, giving 
'ise to nonmarine formations, but these deposits are only a minor 
Dortion of the whole. 

Although the rocks of Florida may appear to indicate continuous 
jedimentation there is good evidence that deposition has at times 
Deen interrupted by periods when the land emerged from beneath 
:he sea and was subjected to erosion. During these periods the 
iction of air and water removed part of the materials already de- 
posited and left an uneven surface. When the land was again 
submerged beneath the sea other materials were deposited upon 
the eroded surface. Such breaks are known as unconformities. 

The same forces which caused the land to rise above sea level 
sometimes operated to produce a slight compression of the strata, 
[n this manner the peninsula was raised in the form of a broad 
arch several hundred feet above the floor of the deep sea. This 
Fact is not readily apparent, because the land surface represents only 
the higher portion of the arch. Minor folds of the strata are also 
known in Florida, but they are mostly inconspicuous and are recog- 
nized with difficulty. 

GENERAL SUCCESSION OF FORMATIONS. 

The time that has elapsed since the oldest known rocks were 
formed in the New World is so long that any attempt to estimate 
its duration in years would be futile. The rocks deposited during 
that time have been divided into several systems, of which only 

65 



66 GEOLOGY AND GROUND WATERS OF FLORIDA. 

the last two are represented in Florida. Of these two the most 
recent is known as the Quaternary and the one immediately pre- 
ceding as the Tertiary. The rocks belonging to the Quaternary 
system are subdivided into two series, known as the Recent and 
the Pleistocene. 

In Florida the Pleistocene began with an uplift that carried the 
surface higher above sea level than it is at the present day. This 
uplift was followed by an interval of extensive erosion, which was 
terminated by a sinking of sufficient extent to carry the lowlands 
beneath the sea. The degree of submergence varied. Later another 
emergence raised the surface of the State somewhat above its present 
altitude. This change in level is regarded as the closing event of 
the Pleistocene epoch. During the Recent epoch slight changes 
have occurred, none of them being of sufficient magnitude to be 
compared with the movements during the Pleistocene. During 
both the Pleistocene and the Recent epochs sand, peat, marl, and 
coquina accumulated over nearly the entire State. 

The rocks belonging to the Tertiary system are commonly grouped 
into four series, of which the youngest is the Pliocene. The Pliocene 
of Florida has been subdivided into five formations which differ 
more or less from each other. They are known as the Lafayette ( ?) 
formation (Pliocene?), the Nashua and Caloosahatchee marls, the 
Alachua clay, and the Bone Valley gravel. The Lafayette ( ?) forma- 
tion is commonly composed of red and yellow sands and sandy 
clays, which cap the hills and uplands of north Florida. The Nashua 
and Caloosahatchee marls consist of sands and marls which contain 
shells of marine organisms. The Alachua clay is commonly sandy 
and locally contains many bones of large land animals. The Bone 
Valley gravel is a phosphatic gravel, which is known as land-pebble 
phosphate. Subsequent to the preparation of this manuscript some 
evidence was obtained that seems to warrant the tentative inclusion 
of the Bone Valley gravel in the Miocene. Though these formations 
are described separately and are represented by three different colors 
on the geologic map (PL I in pocket), it is probable that all of them 
except the Bone Valley gravel are largely contemporaneous. 

Next older than the Pliocene are rocks belonging to the Miocene 
series. These are divided into two formations, known as the Choc- 
tawhatchee marl and the Jacksonville formation, though probably 
deposited at about the same time. The former, which is a shell 
marl, is well exposed in north and west Florida; and the latter con- 
sists of limestone, clay, and sand, known chiefly from well records 
at Jacksonville and farther south along the east coast. 

The oldest rocks known "in Florida belong to the Oligocene series. 
They comprise several formations arranged in two groups, known as 
the Apalachicola group and the Vicksburg group. Of these groups, 



GEOLOGY OF KORTHEEN AKD CEKTBAL FLORIDA. 67 

the younger (Apalachicola) contains four formations — Alum Bluff, 
Chattahoochee, Hawthorn,^ and Tampa. The Alum Bluff formation 
is the youngest, but the other three are believed to be largely con- 
temporaneous. The Alum Bluff formation comprises the typical 
sands and clays which characterize the formation along Apalachicola 
River and elsewhere, together with the Chipola marl. Oak Grove 
sand, and Shoal River marl members. The Vicksburg group includes 
three formations, known as the Ocala limestone, '^ Peninsular" 
limestone, and Marianna limestone. The limestones of the Vicks- 
burg group are especially important because they underlie the entire 
State, and furnish the artesian water in all the large areas where 
flowing wells are obtained. They are exposed in many of the build- 
ing-stone quarries and phosphate mines. The rocks belongiag to the 
oldest epoch of the Tertiary (Eocene) are not exposed in Florida, 
but they occur at the surface in the adjoining States and they doubt- 
less underlie the limestones of the Vicksburg group. 

The following table shows the general succession and character 
of the geologic formations of Florida. 

iThe name of this formation is printed on the map (PI. I) as Hawthorne, the spelling used in some 
previously published reports, but as the geographic name from which it is derived is spelled Hawthorn, 
the final e has been dropped in the text. 



68 



GEOLOGY AND GBOtJND WATERS OF FLORIDA. 



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GEOLOGY OF NOKTHEBN AND CENTRAL FLORIDA. 



69 





Equals land pebble phos- 
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^03^ 

III 




Equals "Floridian 

group." 
"Arcadia marl" regarded 

as a phase of Caloosa- 

hatchee marl. 




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Apalachicola group re- 
places "old Miocene," 
"subtropical Miocene," 
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The "Sopchoppy lime- 
stone" is tentatively 
included in the Alum 
Bluff formation. 




1 

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70 



GEOLOGY AND GROUND WATEBS OF FLOEIDA. 



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GEOLOGY OF NOKTHERN AND CENTRAL FLORIDA. 71 

TERTIARY SYSTEM. 

OLIGOCENE SERIES. 
SUBDIVISIONS. 

The Oligocene rocks may be separated into two groups, called 
here the Vicksburg group and the Apalachicola group. These two 
groups were formerly regarded as Eocene and Miocene, respectively. 
As early as 1846 Conrad ^ referred the rocks exposed at Ballast Point 
near Tampa, together with the prevalent rock of the peninsula, to the 
upper division of the Eocene; and for many years the rocks here 
included in the Vicksburg group continued to be called Eocene by 
numerous writers, including Bailey,^ Tuomey,^ Sniith,* and Dall.^ 
The deposits here called Apalachicola group were first differentiated 
from the Vicksburg in 1887, when Langdon ^ examined the Oligocene 
beds of Apalachicola River and reported that they were Miocene. 
This name was retained for some time but it was modified by the 
use of ''old Miocene" or ''subtropical Miocene" to distinguish it 
from the later Miocene. In 1896 Dall ^ published a brief statement 
of the reason for regarding the so-called Eocene and the so-called 
*'old Mocene" of Florida as Oligocene; and this designation has 
since been followed in many but not in all publications dealing with 
southern Coastal Plain geology. 

VICKSBURG GROUP. 
NOMENCLATURE. 

After the setting apart of the "old Miocene," there remained a 
considerable thickness of rock which was still regarded as Eocene 
and was known as the Vicksburg limestone.^ This name ^ had been 
used to include all the older Tertiary rocks of the peninsula, com- 
prising both the Vicksburgian limestones and the deposits here called 
Apalachicola group, but with the increase of knowledge of the 
geology of the State it was gradually restricted to the older hme- 
stones. Subsequent study indicated that this group of older lime- 
stones, though presenting but slight lithologic variation, was divisi- 
ble on paleontologic grounds into two parts, the lower division (here 

1 Conrad, T. A., Observations on the geology of a part of east Florida, with a catalogue of recent shells 
of the coast: Am. Jour. Sci., 2d ser., vol. 2, 1846, pp. 36-48. 

2 BaUey, J. W., Am. Jour. Sci., 2d ser., vol. 10, 1849, p. 282. 

3 Tuomey, M., A notice of the geology of the Florida keys: Am. Jour. Sci., 2d ser., vol. 11, 1850, pp. 390 
et seq. 

* Smith, E. A., On the geology of Florida: Am. Jour. Sci., 3d ser., vol. 21, 1881, pp. 292-309. 

5 Dall, W. H., and Harris, G. D., Correlation papers— Neocene: Bull. U. S. Geol. Sijrvey No. 84, 1892, 
pp. 101-105. 

6 Langdon, Daniel, jr., Some Florida Miocene: Am. Jour. Sci., 3d ser., vol. 38, 1889, pp. 322-324. 

1 Dall, W. H., Descriptions of Tertiary fossils from the Antillean region: Proc. U. S. Nat. Mus., vol. 19, 
No. 1110, 1896, pp. 303-305. 

8 Bull. U. S. Geol. Survey No. 84, 1893, pp. 101-104. 

9 Smith, E. A., On the geology of Florida: Am. Jour. Sci., 3d ser., vol. 21, 1881, pp. 292-309. 



72 GEOLOGY AND GEOUITD WATERS OF FLORIDA. 

called '^ Peninsular'' limestone) being designated the ''Vicksburg" 
limestone and the upper the Ocala limestone. Still later, Dall ^ pro- 
posed the abandonment of the name Vicksburg as applied to lime- 
stones of the peninsula of Florida and the substitution of the term 
*Teninsular'' for the lower division above described. He states: 

From the observations on the typical Vicksburgian by Col. Casey it seems proba- 
ble that the Orbitoidal limestone which forms the mass of the Floridian Plateau, and 
which has been, in this work and in the literature generally, called the Vicksburg 
limestone, may really form a different horizon altogether from the typical Vicksburg- 
ian and be intermediate between the latter and the nummulitic Ocala limestone. 
In order to promote clearness and avoid confusion, it is probably advisable to adopt 
a distinct name for the Orbitoidal phase or formation, for which I would suggest the 
term Peninsular limestone. This is intended not as a permanent formation name 
but as a general term for the fundamental plateau limestone of Florida, in which a 
close and thorough study may result in the discrimination of more than one horizon 
or zone. 

The reason for the change suggested by Dall is the fact that the 
fossils which have been regarded as characteristic of the Vicksburg 
have been found to occur at other horizons, and hence their occur- 
rence in the limestones which imderlie the nimimiditic rock of the 
peninsula can not be regarded as proof of equivalence of that Hme- 
stone with the limestone at the type locality at Vicksburg, Miss. 
The question of the correlation of the Florida formations is further 
complicated by the fact that two horizons are represented in the 
bluff at Vicksburg. To avoid further confusion, however, the lower 
Oligocene rocks in Florida, originally known as the Vicksburg lime- 
stone, are here designated the Vicksburg group. The group is thought 
to comprise three formations, here called the Ocala limestone, the 
"Peninsular" limestone, and the Marianna limestone. 

The "Peninsular" and Ocala limestones were recognized by Dall; 
and the name Marianna limestone was later given ^ to the soft, 
porous, light-gray to white hmestones of western Florida, which are 
characterized by an abundance of Orhitoides mantelli and other Foram- 
inifera and many other fossils, prominent among which are Peden 
poulsoni and P. perplanus. At the type locality (Marianna, Jack- 
son County) this Hmestone is so soft that it can be cut iato blocks 
with a saw. It contains some beds of chert and many of the fossils 
are silicified. Lithologically the rock at Marianna resembles the 
Ocala limestone at Ocala and the "Peninsular" limestone; but it 
differs from the former in the character of its f aima, especially in the 
absence of nummulites, and it is believed that it may represent a 
horizon below the "Peninsular" limestone of Dall. The close litho- 

1 Trans. Wagner Free Inst. Sei., vol. 3, pt. 6, 1903, p. 1554. 

* Matson, G. C, and Clapp, F. G., Second Ann. Kept. Florida Geol. Survey, 1909, p. 62. 



GEOLOGY OF NOKTHEKN AND CENTRAL FLORIDA. 73 

logic resemblance between the Marianna limestone and the ''Penin- 
sular" limestone, however, makes it possible to combine much of 
the discussion concerning these two formations. 

MARIANNA AND '^PENINSULAR " LIMESTONES. 

StratigrapJiic position. — The base of the ''Peninsular" limestone is 
not exposed in Florida and there is no satisfactory evidence that it 
has been reached in drilling wells; hence the character of the sub- 
jacent formation is not known. Reference has already been made 
to the imcertainty concerning the exact correlation of the "Peninsu- 
lar" limestone of Florida. It will thus be seen that no satisfactory 
conclusions can be drawn concerning the relation which the "Penin- 
sular" limestone bears to the underlying beds. Its relation to the 
overlying formations will be discussed in connection with those 
formations. 

The Marianna limestone is thought to be the stratigraphic equiv- 
alent of the upper part of the bluff at Vicksburg, Miss. Some wells 
ia west Florida enter beds of sand and clay that probably represent 
older formations, but the stratigraphic relation of the Marianna to 
these older beds can not be determined. In west Florida, where 
this formation is recognized, it is unconformably overlain, by beds 
belonging to the Apalachicola group or by post-Pliocene formations. 

Lithologic character. — The Marianna and the "Peninsular" forma- 
tions consist of soft, porous, white or light-gray limestones, in some 
places resembling marl, especially when partly decomposed. Some 
bands of darker-colored dense Hmestone are reported in wells, and 
nodules and layers of chert are common; chert beds are especially 
prominent at certain horizons. For the most part the cherty beds 
are darker in color than the limestone and range in thickness from a 
fraction of an inch to 15 feet. In some locahties as many as six or 
seven successive beds of chert have been encoimtered in a single 
well, the heavier layers being, in general, the more persistent. It is 
usually chert which forms a nearly water-tight cap to the artesian 
water beds in these formations. Certain beds are abundantly fos- 
siliferous, containing innumerable specimens of Orbitoides and 
shells of moUusks, such as Pecten poulsoni. At several locahties the 
rock is so soft that it can be cut into blocks with a saw. On exposure 
to the weather these blocks harden rapidly, making a building stone 
of very fair quahty. Beds of sand, some of them 10 feet or more in 
thickness, are reported in some of the wells that penetrate this for- 
mation. In general these sand beds appear to be most numerous in 
the northwestern part of the State, but even there they are a minor 
part of the formation. 

TTiickness. — The thickness of the "Peninsular" limestone and the 
Marianna limestone appears to be exceedingly variable. The 



74 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

thickness given by Foerste/ from his investigations in southwestern 
Georgia and the adjacent part of Florida, is 220 feet, and probably 
this should be regarded as the approximate measure of the Marianna. 
The thickness of the Vicksburg group is reported by Dall ^ to be 140 
feet at Salt Mountain, Ala., and, on the basis of well borings, is esti- 
mated by the same writer to be over 350 feet at Gainesville, 212 feet 
at Lake Worth, and 1,068 feet at St. Augustine. From recent exam- 
inations of well borings by Vaughan and Bassler limestone of Vicks- 
burg age is known to have a thickness of over 225 feet at Quincy, 
250 feet at Alachua, and 325 feet at Bartow; apparently it thickens 
markedly southward from its exposures in Georgia and Alabama. 
It is hard to estimate just how much reUance can be placed on well 
records, because the drill may penetrate some distance into a forma- 
tion before characteristic fossils are obtained, and it is possible for 
fossils to drop from the side of the bore and thus continue to appear 
in the drillings far below the base of the formation to which they 
belong. Of all the estimates given above the one at Gaiaesville is 
probably the most reliable, because the well is said to be cased to 
the bottom. 

PJiysiograpMc expression. — The '' Peninsular '' limestone and the 
Marianna limestone are characterized by a topography due to solu- 
tion and marked by numerous underground streams, natural bridges, 
sink holes, and large irregular depressions. That the underground 
streams in these formations attain considerable size is shown by a 
number of large springs which emerge apparently from definite 
channels. The most noted natural bridge of the Marianna lime- 
stone is on Chipola River near Marianna; but there are many others 
of smaller size, both in this formation and in the '^ Peninsular" lime- 
stone. Wherever the limestone lies near the surface, rounded hills 
and sink holes characterize the topography; the siaks form many lake 
basins in the central part of the peninsula. 

Pdleontologic character. — ^Both the ''Peninsular" limestone and 
the Marianna limestone are characterized by an abundant fauna, 
the most promuient fossil being Orhitoides mantelli, with which is 
associated Pecten foulsoni and P. perplanus. Dall ^ says that the 
fauna of the ''Peninsular" limestone includes about 222 species, of 
which 102 are restricted to it. With the imperfectly known fauna 
of the Ocala limestone it has 15 species in common; 9 species continue 
iQto the "silex bed" and limestone of the Tampa formation, and 2 
continue into the Miocene and down to the Recent fauna. 

Structure. — The "PeniQsular" limestone and the Marianna lime- 
stone have been affected by the earth movements which have pro- 

1 Foerste, A. F., Am. Jour. Sci., 3d ser., vol. 48, 1890, p. 46. 

2 Bull. U. S. Geol. Survey No. 84, 1892, p. 103. 

8 Trans. Wagner Free Inst. Sci., vol. 3, pt. 6, 1903, pp. 1553. 



GEOLOGY OF NORTHEBN" AND CENTRAL FLORIDA. 75 

duced the present structure of the State. Their major structural 
feature consists of a broad anticHne. The dips are low and are 
generally seaward. Local variations in altitude of the surface of 
these limestones are so pronounced as to suggest that there has been 
considerable local warping as well as a general arching. Toward the 
southern end of the State the '^Peninsular" limestone dips southward 
beneath the Everglades, where it is probably buried under some 
hundreds of feet of younger sediments. Along the east coast tliis 
formation shows marked variations in depth; nowhere, however, 
does it rise to within less than 175 feet of the surface, and at Jackson- 
ville it lies at least 525 feet below the surface. 

At Tampa, on the west coast, the '^ Peninsular" limestone probably 
lies somewhat more than 100 feet below the surface, but farther 
north along the coast it may be exposed. Apparently the dip of the 
Marianna limestone toward the southwest in the long western exten- 
sion of the State is very rapid, for at Pensacola this limestone is 
buried more than 1,100 feet beneath younger sediments. 

Areal distribution. — As early as 1849 limestone of Vicksburg age 
was noted by J. W. Bailey,^ who obtained some '^Orbitulites" from 
a chert at Pyles plantation, about 40 miles west of Palatka. The 
locality where these specimens were obtained is only a few miles 
south of Ocala. The same writer mentions the occurrence of similar 
rock at several points between Palatka and Tampa, but in no case 
does he give the exact localities. 

While collecting statistics for the Tenth Census, Smith ^ gathered 
much valuable information relating to the geology of Florida. He 
presented evidence to show that limestone of Vicksburg age under- 
lies nearly the entire peninsula of Florida, giving in part its areal 
outcrop and noting the occurrence of Orhitoides mantelli, Pecten 
poulsoni, and other characteristic fossils in exposures of the lime- 
stone here called Marianna a few miles southeast of Campbellton, 
at the Big Spring, east of Marianna, and at other localities which he 
does not name. From a limestone collected by him 6 miles from 
St. Marks, in Wakulla County, Heilprin identified Orhitoides mantelli, 
and pronounced the rock to be Vicksburg; but the rock at St. Marks 
belongs to the Apalachicola group instead of to the Vicksburg group. 
Smith examined a marl which occurs at various points along the 
Gulf coast and decided that it also was of Vicksburg age. He states 
that it forms the basis of the ''gulf hammock" land in the coastal 
counties from Wakulla County nearly to Tampa Bay in Hillsborough 
County. In describing the areal extent of the Vicksburg, Smith 
included in it large areas of rock which are now known to belong to 
the upper Oligocene or Apalachicola group; for example, the lime- 

» Bafley, J. W., Am. Jour. Sci., 2d ser., vol. 2, 1851, p. 86. 
:Smith, E. A., On the geology of Florida: Am. Jour. Sci., 3d ser., vol. 21, 1881, pp. 292-309. 



76 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

stone extending along Suwannee Kiver for many miles and the lime- 
stone at Tampa. He called attention to the fact that the limestones 
of the Vicksburg group prevail in the vicinity of Gainesville and that 
in many places they are composed largely of Orhitoides mantelli. 
Other localities included in the Vicksburg were Paynes Prairie and 
Ocala. 

In addition to the localities mentioned above, Smith reports lime- 
stone of Vicksburg age at Live Oak and Lake City, in the northern 
part of the peninsula. At these localities, as in many other parts of 
the peninsula, the formation is overlain by a few feet of younger 
rock. Dall ^ gives the following summary of localities where the 
Vicksburg has been observed: 

It is impracticable with the data yet printed to determine exactly at how many of 
Smith's localities the country rock belongs to the Orbitoides horizon. Some of them, 
doubtless, will eventually be shown to be of later age, as will be indicated later in this 
summary. Only those where no doubt seems to exist will be specified here. In 
Alachua County it is widespread, having been observed by Smith and Dall at Gaines- 
ville and westward to and about Archer, though in many places overlain by solution- 
ary residuum, remnants, or even beds of later age but moderate thickness. It had been 
identified at Silver Spring, 6 miles east from Ocala, by Le Conte, as early as 1861,^ and 
subsequently the observation has been confirmed by Smith. Specimens of this rock 
have been collected by Willcox at Martin station, Marion County, about 8 miles north of 
Ocala, where the rock is very cherty; and at Jarves's spring, on the southern border of 
Pasco County; at Fort Foster, on the North Fork of the Hillsboro River, where, as in 
many other places, relics of the old Miocene beds overlie it. Several of the localities 
referred to by Heilprin must remain for the present on the doubtful list, but among 
them should hardly be counted the islet at the mouth of Homosassa River, from which 
Mr. Willcox obtained the Pygorhynchus (Ravenelia) gouldii Bouve, a small echinoderm 
originally described from the buhrstone (ante-Claibornian) of Georgia. 

It will be seen from this quotation that later investigations indicate 
that the limestone at some of the localities mentioned by Smith is not 
of Vicksburg age. However, this should not be regarded as de- 
tracting from the value of the earlier work, for with the increase of 
knowledge it is inevitable that formation lines should be shifted and 
that new formations should be discriminated. 

Miss Maury's ^ summary of the Vicksburg indicates that it forms a 
large part of the country rock in north-central Florida, and she cites 
many of the localities mentioned by Dall and Bailey. She mentions 
especially the exposures seen in the vicinity of Gainesville, which are 
surrounded by rocks belonging to the division here called Apalachi- 
cola group. Attention is also called to the occurrence of gypsum, 
which is regarded as the result of the action of sulphur on calcium 
carbonate, and the occurrence of phosphate rock, resulting from an 
analogous chemical action. 

iBuU. U. S. Geol. Survey No. 84, 1892, pp. 102-103. 

2 Am. Jour. Sci., 2d ser., vol. 21, 1861, pp. 1-12. 

3 Maury, C. J., The Oligocene of western Europe and southern United States: Bull. No. 15 Ana. Paleontol- 
ogy, vol. 3, 1902, pp. 45-46. 



GEOLOGY OF NOETHERN AND CENTRAL FLORIDA. 77 

During the progress of recent field work the occurrence of the Mari- 
anna limestone was noted at Natural Bridge, in north-central Walton 
County, but there is no indication that it reaches the surface west of 
this county; indeed, from well records and exposures of other forma- 
tions, there is every reason to believe that in Escambia and Santa 
Rosa counties this formation lies some hundreds of feet below the 
surface of the upland. 

East of Marianna the formation is exposed at several localities 
where it presents considerable variation in its lithologic characteris- 
tics. At some of these localities it is a soft porous white limestone, 
and at others it is a tough dense gray limestone. However, some of 
this difference in texture may be accounted for by the fact that the 
rock hardens on exposure to the air, and it is perhaps significant that 
the hard gray limestone is usually seen at natural exposures and the 
soft porous rock at quarries. 

Near the east edge of the town of Marianna a small exposure affords 
the following section: 

Section No. 1, near east edge of Marianna. 

Lafayette (?) formation: Feet. 

Clay, red, sandy; some beds of sand and gravel 25 

Marianna limestone : 

Clay, white, marly 5 

Limestone, hard, earthy, gray 2 

Marl, blue, with many Pectens 8 

Limestone, hard, gray 4 

Section No. 2 {approximately 20 feet below section No. 1). 

Limestone, hard, gray, very fossiliferous; contains Orbitoides man- Feet. 

telli, Pecten poulsoni, etc 5 

Chert, dark gray J 

Limestone, soft, porous, white; a few Orbitoides and other fossils... 30 

The white limestone of this section is exposed in a quarry, where it is 
obtained by sawing. It is used locally for building, especially in the 
construction of chimneys. Upon exposure to the weather the rock 
hardens until it resembles the hard member at the top of the section. 

A well drilled at Marianna penetrated limestone, marl, and clay 
to the depth of 265 feet, where a bed of quicksand was encountered. 
An incomplete log of this well is given below. 

Log of well at Marianna. 

Depth. 




Sand and sandy loam (Pleistocene) 

Clay, red and yellow, sandy, and sand (Lafayette(?)) 

Limestbne, hard, and marl, alternating beds; doubtless includes section No. 1 at the 

east end of the town 

Hard rock (chert); followed by alternating beds of marl and limestone with some 

chert (Marianna limestone (?)) 



Feet. 
21i 

266i 



78 GEOLOGY AND GKOTJND WATEBS OF FLOEIDA. 

The log of this well does not afford any means of judging at what 
depth the base of the Marianna limestone was reached, but it is 
possible that an underlying formation was entered some distance 
above the bottom of the well. 

At a locahty 2^ miles southeast of Chipley, the Marianna limestone 
outcrops in the edge of a sink, and about 6 miles southwest of Chipley 
and 1 mile north of Duncan it is exposed in some small quarries where 
it had been obtained for building stone. At one of these quarries, 
belonging to F. G. Owens, the rock has also been burned for lime, 
which was reported to be of good quality. This quarry shows about 
20 feet of porous white limestone, resembling the rock in section 
No. 2 at Marianna. Near the surface it is very hard and durable, 
but at greater depths it is much softer. 

Fossils occur throughout the section, but they are especially 
numerous in the upper 5 feet, where the rock appears to be largely 
composed of Orhitoides mantelli. A weU-defined ridge at the quarry 
appears to consist of the Marianna limestone covered b}^ a few feet of 
white Pleistocene sand and sandy loam, the presence of the Marianna 
being indicated by numerous bowlders containing characteristic 
organic remains. 

A few miles northeast of Duncan, at Falling Water, a large sink 
exposes several feet of light-gray limestone, probably belonging to 
the Marianna. At this locality there appears to be a well-defined 
system of underground drainage, which is indicated at the surface 
by numerous sink holes. The best exposure is seen where a small 
stream plunges into one of these sink holes with a reported fall of 
over 70 feet. The rock, however, forms a nearly perpendicular cliff 
and is not easily accessible. 

At Natural Bridge, near the north line of Walton County, a light- 
gray to yellowish-gray marl forms the arch which spans a small 
stream. The width of the channel is probably 20 feet and the length 
of the bridge about one-fifth mile. The height of the exposure above 
the level of the water in the creek was estimated by Vaughan ^ to 
be 35 to 40 feet. When fresh the rock is soft and crumbles readily 
in the fingers, but when exposed to the weather it hardens rapidly 
and assumes the yellowish color mentioned above. It is quarried 
by sawing, and is locally known as ^'chimney rock," because it is 
used in the construction of chimneys. A considerable percentage of 
clay, which occurs in fine particles distributed through the rock, 
indicates that the material is a marl rather than a limestone. Pecten 
poulsoni is the most abundant fossil. From the lithologic character 
of the rock, together with the occurrence of numerous specimens of 
the species mentioned above, the rock is considered to belong to the 
Marianna limestone. 

1 Vkughan, T. W-., unpubljslied notes. 



GEOLOGY OF NOETHEEN AND CENTEAL FLOEIDA. 79 

A quarter of a mile south of Natural Bridge, near a turpentine 
still, a similar marl outcrops in the bed of a small stream with a 
thickness of about 20 feet. This rock is slightly more compact than 
that described above and has a distinctly grayish or bluish color. 
These differences, however, are probably due to the fact that it has 
not suffered so much weathering as the rock at the Natural Bridge, 
and its substantial equivalence with the latter can hardly be ques- 
tioned. Numerous concretions of nearly pure carbonate of lime are 
scattered throughout this marl, but they do not appear to have any 
relation to the occurrence of the fossils. 

About 7 miles southwest of Marianna and nearly 1 mile from 
Kynesville, a number of fragments of limestone ^ere obtained from a 
field, where they were said to have been turned up by the plow. They 
represent a very cherty phase of the Marianna limestone and are 
probably residual products of weathering. They consist of bowlders 
up to 2 or 3 feet in diameter, which contain innumerable specimens 
of Orhitoides mantelli and Pecten poulsoni. 

At the phosphate mines in the vicinity of Croom, where a number 
of specimens of Orhitoides mantelli were collected, the rock has the 
lithologic characteristics of the ''Peninsular" Hmestone. The collec- 
tion was made from bowlders dredged from a mine, and it is difficult 
to decide whether it is ''Peninsular" or Ocala limestone. The pres- 
ence of a number of specimens of Cassidulus suggests that limestone 
belonging to the Apalachicola group is also represented. In the 
absence of characteristic Nummulites in the collections, it appears 
not unhkely that the limestones of the Apalachicola group may here 
rest upon the "Peninsular" limestone. However, this conclusion is 
made subject to revision in case future collections from this locality 
should reveal the presence of fossils belonging to the Ocala limestone. 

The "Peninsular" limestone is known to outcrop throughout the 
central part of the peninsula, where it may be observed in numerous 
natural and artificial exposures. It has been encountered in many 
of the hard rock phosphate mines from Croom northward nearly to 
the north line of the State. It is also known to underUe a large part 
of the central lake basin of the peninsula, and it is encountered in 
wells along the east coast from Fernandina southward to beyond 
Palm Beach and along the west coast south of Tampa. 

OCALA LIMESTONE. 

Nomenclature. — The Ocala limestone was formerly regarded as part 
of the "Orhitoides limestone," but in 1882 Nummuhtes derived from 
waste products of the Hmestone were described by Heilprin.^ The 
specimens were obtained by Willcox from Chassahowitzka Kiver, 

1 Heilprin, Angelo, On the occvirrence of nummulitic deposits in Florida and the association of Num- 
mulites with a fresh-water fauna: Proc. Philadelphia Acad. Nat. Sci., 1882, pp. 189-193. 

76854°— wsp 319—13 6 



80 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

and their association with fresh-water forms of recent shells was 
rightly interpreted to mean that the JSTummuhtes had been trans- 
ported from some other locality and redeposited with the younger 
shells. In 1884, Willcox ^ announced the occurrence of the nummu- 
Htic rock in place some distance above the original locaHty on Chassa- 
howitzka River, and Heilprin, in commenting on the announcement, 
stated that the beds belonged to the OHgocene. 

The rock occurs at the old Confederate iron works in Levy County 
where it was given the name ^'Levyville formation'' by Johnson,^ 
who described it as consisting of about 20 feet of soft porous building 
stone. He believed that it had been partly removed by erosion in the 
western part of the pjBninsula, where it is much thinner than farther 
east, but expressed doubt as to its having been deposited over the 
entire surface of the underlying ''Peninsular" limestone. 

Johnson mentioned several other localities where this formation 
was recognized, among them being Paynes Prairie. He reported that 
at a quarry on the Noonanville road near Santa Fe River the Neocene 
formations rested directly upon the ''Peninsular" limestone, the 
nummulitic rock (Ocala limestone) being absent. Johnson's Levy- 
ville formation has usually been regarded as the substantial equivalent 
of the Ocala limestone; but it is not possible at present to verify the 
determination of the nununulites, and the rocks at Levyville may 
really belong to some other formation. 

In subsequent publications by Heilprin this rock was called 
"Nummulitic" limestone, but in 1892 DalP proposed the name 
Ocala limestone. He states: 

Among the rocks which until recently were not discriminated from the Orbitoides 
limestone, and which appear in central Florida directly and conformably to overlie 
the latter, though no one has described their contact, is a yellowish friable rock con- 
taining many Foraminifera, conspicuous among which are two species of Nummulites, 
N. willcoxii and N. floridana Hp. This rock was first brought to notice by Mr. Joseph 
Willcox, and to Prof. Heilprin we owe a description of it which discriminates between 
it and the Vicksburg or Orbitoides rock. The rock was early recognized as Eocene, 
though not discriminated from the earlier beds. It is best displayed at Ocala, Fla., 
where it forms the country rock, and has been quarried to a depth of 20 feet without 
coming to the bottom of the beds. 

StratigrapMc position. — The Ocala limestone lies stratigraphically 
between the "Peninsular" limestone and the beds here designated the 
Apalachicola group. Lithologically, it bears a strong resemblance 
to the underlying "Peninsular" limestone, with which it also has 
close f aunal relation. These facts have led to the conclusion that the 
two formations are conformable, and it has also been suggested 
that the Ocala limestone is a local phase of the "Peninsular" lime- 

1 Science, new ser., vol. 3, 1884, p. 607. 

2 Johnson, L. C, Am. Jour. Sci., 3d ser., vol. 26, 1883, pp. 230-236. 
8 Bull. U. S. Geol. Survey No. 84, 1892, pp. 103-104. 



U. S. GEOLOGICAL SUF?VEY 



WATER-SUPPLY PAPER 319 PLATE IX 




A. SECTION IN QUARRY OF OCALA LIME CO. AT OCALA. 




B, QUARRY OF OCALA LIME CO. (OLD PHILLIPS QUARRY) 1 MILE SOUTHEAST OF OCALA. 



GEOLOGY OF NOETHERN AND CENTEAL FLORIDA. 81 

stone. Although the two formations are probably conformable, the 
extensive distribution of the nummulites of the Ocala limestone 
shows that it represents a widespread change in conditions and is 
not to be classed as a mere local phase of the imderlying beds. 

The Ocala limestone, as already noted by Johnson, is in places 
wanting, so that the overlying formations rest directly upon the 
''Peninsular" limestone. 

Lithologic character. — The Ocala limestone consists of a soft, 
porous, light-gray to white limestone which bears a strong lithologic 
resemblance to the underlying ' 'Peninsular" limestone but is dis- 
tinguished from it by the included fossils. When slightly weathered, 
the rock becomes light yellow, and owing to its granular appearance 
is often regarded as a sandstone. The removal of the calcareous 
material by the leaching action of underground water leaves a pale 
yellow, more or less incoherent sand, containing a small percentage 
of calcium carbonate. When fresh, the Ocala limestone is so soft 
that it is easily broken, but many exposed surfaces become hardened 
by the deposition of calcium carbonate by waters emerging along 
the outcrop. For this reason the rock locally appears to be hard and 
firm. Its porosity and ready solubility permit the formation of 
numerous underground channels which appear in some of the out- 
crops and are elsewhere inferred from the numerous sink holes. (See 
PI. IX, B.) The rock contains an abundance of organic remains 
which are commonly preserved as casts. Nodules and large masses 
of chert are also common and in some localities a large part of the 
rock has been siUcified. (See PL IX, A.) 

TJiicJcness. — No definite determination of the maximum thickness 
of the Ocala limestone has been made, and as yet no exposures have 
been observed which show the contact with the underlying ''Penin- 
sular" hmestone. All the information now available indicates that 
the thickness is variable and that the variation is probably in con- 
siderable measure due to subsequent erosion rather than to the 
inequalities of deposition. Dall * states that at the type locality the 
Ocala limestone has been quarried to a depth of 20 feet without reach- 
ing its contact with the underlying "Peninsular" limestone. The 
greatest thickness noted during the recent field investigation was in 
a sink hole near Ocala, in which the formation is exposed to a depth 
of about 40 feet without reaching its base. 

Physiographic expression. — ^As in the case of the "Peninsular" 
limestone, the Ocala limestone is soft and porous and hence gives 
rise to a topography characterized by low hiUs, gentle slopes, sink 
holes, sinking streams, and natural bridges. This limestone has 
had an important influence in the development of many of the lake 

1 Dall, W. H., Trans. Wagner Free Inst. Sci., vol. 3, pt. 6, 1903, p. 1555; 



82 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

basins, and it forms the natural bridge over Santa Fe River near 
High Springs. In the central portion of the peninsula underground 
streams are common and many large springs emerge from the Ocala 
limestone. 

Paleontologic character. — ^The Ocala limestone, like the underlying 
''Peninsular" limestone, is characterized by a great number of 
Foraminifera, but it differs from the latter in the presence of Num- 
mulites. A few moUusks are said to be restricted to this formation, 
but as yet the fauna is very imperfectly known, and future study may 
add to the number of fossils known to be peculiar to it. 

Structure. — ^The Ocala limestone shows the same structural features 
as the underlying ''Peninsular'^ limestone, both formations having 
doubtless been subjected to the same deformation since their deposi- 
tion. 

Areal distribution. — It was in 1882 that Joseph Willcox discovered 
a rock in the vicinity of Chassahowitzka River which he submitted 
to Heilprin * for identification. The presence of Nummulites wa-s 
regarded as an indication that a new formation had been discovered. 
In 1886 Heilprin ^ added to the published list of localities where the 
nummulitic fauna was known to occur a spot near Arredonda, about 
6 miles southwest of Gainesville, where Nummulites floridanus had 
been collected by G. A. Wetherby and Joseph Willcox. 

In 1902, after summarizing the results of previous investigations, 
DalP mentions certain new localities of the Ocala limestone, as follows : 

Since then Mr. Willcox has obtained the rock in place 15 miles northeast of the 
original locality, from the shore of Waccassassa Bay, near Cedar Keys, and also from 
tlie banks of Waccassassa River, Levy County; from a "sink hole" at Pemberton's 
ferry on Withlacoochee River, about 10 miles eastward from Brookville, and also at 
Bayport, Hernando County, and at various places about Ocala. Prof. Wetherby has 
also sent specimens from a well 5 miles southwest of Gainesville, Alachua County, and 
Mr. L. C. Johnson reports it from an old Confederate iron furnace, 3 miles north of 
Levyville, Levy County, where it is only 20 feet thick and is covered with a bed of 
bog iron ore, formerly worked. Pemberton's ferry is the most southern point at which 
it has been recognized at the surface, but at Bartow, Polk County, it occurs covered 
by about 6 feet of later strata. 

From the character of its included organic remains the exposure at 
Martin station as regarded by Dall ^ as equivalent to the Ocala lime- 
stone. At this locality the rock is more or less silicified and has been 
found useful for railroad ballast, road metal, and other purposes where 
durable material is needed. 

The Ocala limestone is extensively exposed at the type locality, 
where it has been quarried for the construction of roads and the 

1 Heilprin, Angelo, Proc. Philadelphia Acad. Nat. Sci., 1882, pp. 189-193. Abstract in Am. Jour. Sci/,.; 
3d ser,, vol. 24, 1882, p. 294. 

2 Heilprin, Angelo, Notes on the Tertiary geology and paleontology of the southern United States: Am, 
Jour. Sci., 3d ser., vol. 29, 1885, p. 69. 

3 Bull. U. S. Geol. Survey No. 84, 1902, p. 104. 

4 Trans. Wagner Free Inst. Sci., vol. 3, pt. 6,1903, pp. 1156-1157. 



GEOLOGY OF NORTHEEN AND CENTRAL FLORIDA. 83 

manufacture of lime. Some exposures are seen in the walls of sinks, 
and its presence may be inferred by the appearance of numerous 
bowlders containing Nummulites. These scattered fragments are 
frequently found resting upon surface sands and are mostly rather 
firmly cemented, probably by an accumulation of silica and iron. 
A thin deposit of sand, commonly found resting upon the uneven 
surface of the limestone, appears to be largely the result of disinte- 
gration of the country rock, and is therefore residual. The residual 
sands constitute the impurities of the original rock and may have 
formed only a small percentage of the whole. 

Since the publication of DalFs report quarrying at Ocala has been 
carried to a somewhat greater depth. The quarry oi the Ocala Lime 
Co., situated near the southwest corner of the city, now shows the 
following section: 

Section in quarry of Ocala Lime Co., Ocala. 

Feet. 
Loam, sandy, with more or less organic matter (Pleistocene or 

Pliocene) « 1 

Sand, pale yellow, residual 1-4 

Limestone, light gray to white, nummulitic (Ocala) 25-30 

In this quarry the fossils occur throughout the greater portion of 
the limestone but are especially numerous near the top, where the 
removal of the calcium carbonate has loosened the casts of the organic 
remains. Chert nodules occur in various parts of the section, and in 
places two sets of vertical siliciiied bands were noted. These cherty 
bands are locally approximately at right angles to each other and 
probably represent planes of silicification along vertical joints. 

A good section of this limestone is exposed in another quarry sit- 
uated on the north side of the road to Silver Spring, about one-half 
mile east of the town. At this locality the rock, which is considerably 
decomposed, has been quarried to a depth of 40 feet and contains an 
abimdance of Nummulites. 

About 20 feet of Ocala limestone is exposed in a third quarry 
situated one-fourth mile north of Ocala, and about 15 feet of the same 
rock was seen in a quarry 2 J miles southwest of the city. One of the 
most important sections may be seen about 3 miles southwest of 
Ocala in a sink hole approximately 40 feet deep, which affords 
entrance to a small cavern which may be penetrated for a short dis- 
tance. Clapp reports that Nummulites occur down to the base of 
this exposure but are not so numerous as at some of the other local- 
ities. Lithologically this rock is essentially the same as that exposed 
at the quarry of the Ocala Lime Co., and the section shows the maxi- 
mum observed thickness of the formation. 

"■ Since this manuscript was prepared it has been learned that the vertebrate fossils from the Ocala 
mentioned on p. 143 were obtained from this sandy loam. 



84 GEOLOGY AND GKOUND WATERS OF FLORIDA. 

A section at the old '^Phillips" quarry, a mile southeast of Ocala, 
shows about 25 feet of soft, porous, light-gray limestone, which con- 
tains an abundance of chert disseminated throughout the section. 
As this rock contains many Nummulites, its identification as the Ocala 
limestone can scarcely be questioned. Solution cavities are common, 
and along certain vertical crevices the rock has been removed, form- 
ing passages 2 to 3 feet in width, which have been filled by the 
settling of the overlying sandy clay. 

On Anclote Kiver, about a mile from Tarpon Springs, an exposure 
extending some distance up the stream shows from 2 to 3 feet, of 
Ocala limestone. The rock here lies near the surface over a consid- 
erable area, and bowlders containing Nummulites are common. A 
similar exposure of Ocala limestone was noted near Port Richey on 
Pithlachascotee River, where the rock is said to outcrop over a con- 
siderable area. At the mine of the Fort White Rock Phosphate Co., 
one-half mile southwest of the railroad station, the Ocala limestone 
is well exposed. In the north pit belonging to' this company the 
following section was observed : 

Section in quarry of Fort White Rock Phosphate Co., near Fort White. 

Feet. • 

Loam, light gray, sandy (Pleistocene) 4-8 

Sand, fine, even grained, yellow (residual) 20 

Limestone and phosphate rock (Ocala) 25-30 

In this pit the Ocala limestone occurs in irregular ledges separating 
the phosphate rock, which appears to be in part the result of replace- 
ment of the Ocala. The limestone ledges commonly form two dis- 
continuous series at approximately right angles to each other, the 
intervening space being occupied by the irregular bodies of phos- 
phate rock. In general, the limestone bands thicken toward the base 
of the pit and the phosphate deposits become smaller. Both the 
limestone and phosphate are more or less cherty, but the silicifica- 
tion appears to be in the form of nodules and small bowlders rather 
than to constitute an extensive replacement. Fossils are very abun- 
dant in the limestone, prominent among them being the character- 
istic Nummulites of this formation. At the mine of the Cummer 
Lumber Co., 4 miles west of High Springs, the Ocala lies much 
nearer the surface, the total thickness of overlying sand being in few 
places greater than 10 feet. There is the same characteristic arrange- 
ment of the limestone and phosphate rock as at Fort White. 

Similar relations between the Ocala limestone and the phosphate 
were observed at the mine of the Union Phosphate Co., 7 miles east 
of JN^ewberry. The Alachua sink was visited by Clapp, who reports 
an exposure of about 10 feet of soft white limestone containing many 
flint nodules. From the collections made at this locality it is evi- 
dent that the Ocala limestone forms part of the walls of the sink, 



GEOLOGY OF NORTHEKN AND CENTRAL FLORIDA. 86 

and it also appears probable that the overlying Hawthorn formation 
is present. On the island opposite Melbourne, Sellards reports the 
occurrence of the Ocala limestone at a depth of 222 feet, basing this 
determination on a large fragment containing Nummulites, which 
was obtained in drilling a well; although the specimens were not spe- 
cifically determined, the occurrence of the genus appears to warrant 
the correlation of the rock with the Ocala limestone. This is a point 
of special interest, because it shows the Ocala limestone to be nearer 
the surface in that part of the State than would have been inferred 
from previous publications. 

The Ocala limestone is known to be well exposed at various points 
in the region where rock phosphate is being mined. Nummulites 
have been collected from various mines in the vicinity of Hernando, 
Citrus County. In a pit in sec. 10, T. 18 S., R. 19 E., a section was 
observed consisting of 2 to 3 feet of yellow sand, with phosphatic 
gravel and brown and yellow clays, and phosphatic white and gray 
sand, in places greenish, the whole underlain by phosphatic bluish- 
gray clays, containing some hard sandstone with bowlders of hard 
rock phosphate containing Nummulites. The entire section prob- 
ably represents altered and weathered phosphatic Ocala limestone. 

Nummulites were also obtained by Eldridge from a stone quarry 
on the Burns place, IJ miles southwest of Owensboro, Citrus County, 
and from Mr. Clement's mine No. 8, on the east side of Blue Springs, 
T. 16 S., R. 19 E. 

" Miliolite limestone." — In 1887 Heilprin ^ noted at Wheelers, on 
Homosassa River, the occurrence of a porous and cavernous lime- 
stone which he called '^Miliolite limestone" because of the presence 
of many Foraminifera belonging to the MUiolidse. DalP reports simi- 
lar rock 6 miles southwest of Lake City; he thinks the ''Miliolite 
limestone " belongs with the other f oraminif eral limestones but does 
not express an opinion as to whether it belongs with the ' ' Peninsular " 
or the Ocala limestone. The ''Miliolite limestone" is here placed 
with the Vicksburg group and is tentatively referred to the Ocala 
limestone, to which it probably belongs. 

APALACHICOLA GROUP. 

NOMENCLATURE. 

Prior to 1887 the rocks belonging to the subdivision of the Oligo- 
cene, here designated the Apalachicola group, from its exposures along 
Apalachicola River in western Florida, were included with the Eocene 
and were regarded as part of the Vicksburg. In 1887, however, 

1 Heilprin, Angelo, Explorations on the west coast of Florida: Trans. Wagner Free Inst. Sci., vol. 1, 
1887, p. 57. 

2 DaU, W. H,, Bull. U. S. Qeol. Survey No. 84, 1892^ pp. 104r-105. 



86 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

Langdon ^ described beds occurring on Apalachicola River, referring 
them tentatively to the lower Miocene and designating them the 
Chattahoochee group. With the Miocene beds, Dall,^ in 1892, in- 
cluded not only the Chattahoochee group of Langdon but the Haw- 
thorn formation, the '^ Waldo formation," the '^ Tampa limestone,'' 
the ^' Tampa silex bed," the Chipola marl, the Alum Bluff formation, 
and certain sands, gravels, and clays which he did not specifically 
name. 

The use of the name Miocene to designate the group here called 
Apalachicola continued for a number of years, the Oligocene beds being 
often called ''old Miocene" or ''subtropical Miocene," to distinguish 
them from the "new Miocene" or "cold-water Miocene." In 1896 
DalP discussed the faunal reasons for regarding the "old Miocene" 
as Oligocene, and in his publications since that date he has restricted 
the term Miocene to later beds (here called Jacksonville formation and 
Choctawhatchee marl). However, the Chattahoochee formation is 
still included in the Miocene by both Smith * and McCallie ^ in their 
latest publications. 

The Apalachicola group was formerly designated "upper Oligocene 
or Chipolan stage"® and "Chipola group," ^ but these names are 
abandoned because the name Chipola has been used to designate a marl 
belonging to the upper formation of the group. 

The Apalachicola group includes a number of beds which differ 
widely in lithologic character but which are recognized by their 
fossils as integral parts of a single group. Limestones and marls 
predominate, but the group also includes beds of nearly pure sand and 
clay. The entire period of deposition appears to have been charac- 
terized by the accumulation of more or less terrigenous materials, 
rendering most of the limestones impure by admixture of clay and 
sand. At certain times the conditions appear to have been especially 
favorable for the development of organic life, and some members, 
such as the Chipola marl member of the Alum Bluff formation and the 
"silex bed " of the Tampa formation, contain very large faunas. 

Owing to the lithologic variations and widely separated exposures, 
the exact correlation of the formations of the group is dependent on 
the organic remains they contain; and, although the paleontologic 
studies, especially those of Dall, have shed much light on the strati- 

1 Langdon, D. W., jr., Some Florida Miocene: Am. Jour. Sci., 3d ser., vol. 38, 1889, pp. 322-324. 

2 Bull. U. S. Geol. Survey No. 84, 1892, pp. 105-123. 

s Description of Tertiary fossils from the Antillean region: Proc. IT. S. Nat. Mus., vol. 19, No. 1110, 1896, pp. 
303-305. 

* Smith, E. A., The underground water resources of Alabama: Geol. Survey Alabama, 1907, p. 81. 

6 McCallie, S. W., Prehminary report on the underground waters of Georgia: Geol. Survey Georgia, 1908, 
pp. 31 and 32. 

6Dall,W.H., A table of North American Tertiary horizons: Eighteenth Ann. Kept. U. S. Geol. Sur- 
vey, pt. 2, 1898, p. 334. 

7 Foerste, A. H., Studies on the Chipola Miocene of Bainbridge, Ga., and of Alum Bluff, Fla.: Am. Jour. 
Sci., 3d ser., vol. 46, 1893, p. 244. 



GEOLOGY OF NOETHEKN AND CENTRAL FLORIDA. 87 

graphic relations of the different beds, many points are as yet unde- 
cided. For this reason it seems best to retain the old names of certain 
formations and to indicate as far as possible their relationships. The 
Apalachicola group, therefore, is described as consisting of four forma- 
tions, the Chattahoochee, the Hawthorn, the Tampa, and the Alum 
Bluff. There is some reason for believing that the first three are, in part 
at least, synchronous, but exact equivalence is difficult to determine 
where outcrops are widely scattered and faunal studies are incomplete. 
The Alum Bluff formation is clearly younger than the Chattahoochee 
formation, upon which it rests. 

The name Chattahoochee group was first applied by Langdon* 
to the beds occurring at a series of outcrops along Chattahoochee and 
Apalachicola rivers. The localities examined by Langdon extend 
from the final outcrops of the Vicksburgian, 9 miles by water above 
River Junction (Chattahoochee), to where the Oligocene outcrops 
give place to the overlying sands and marls of younger formations. 
The outcrops examined are at Alum Bluff, Rock Bluff, Ocheesee, and 
River Junction. 

In 1893 the section along Apalachicola River was examined by 
Foerste,^ who recognized the presence of three dissimilar groups, to 
which he gave the names Chattahoochee, Chipola, and Chesapeake. 
His paper gives considerable attention to the character of the materials 
comprising his Chipola and Chesapeake groups, with a view to corre- 
lating them with the nonmarine deposits grouped under the name of 
''Grand GuK and Lafayette formation." The major portion of the 
discussion, however, deals with the conditions of sedimentation during 
the deposition of the rocks belonging to the various groups. 

In 1892 DaU^ divided the formations here included in the Apa- 
lachicola group into two groups, retaining the name Chattahoochee 
group for the limestones and marls, which are extensively developed 
in the northern part of the State, and applying the name Tampa group 
to the beds which he called Chipola marl. Alum Bluff sands, Sopchoppy 
limestone, Tampa limestone, and Tampa silex bed. In his later paper 
on the Tertiary faunas of Florida, Dall places the ''silex bed" at 
Tampa in his Chattahoochee group. The discovery of the character- 
istic species of the genus Orthaulax in the basal portion of the Chat- 
tahoochee formation led to this change in the correlation. 

HAWTHORN FORMATION. 

General character. — In* 1892 Dall * described, under the name 
Hawthorne beds, some limestones, sands, and clays extensively 
exposed in the interior of Florida. These beds are here designated 

1 Langdon, D. W., jr., Some Florida Miocene: Am. Jour. Sci., 3d ser., vol. 38, 1889, p. 322. 

2 Foerste, A. H., op. cit., pp. 244-254. 

3 Bull. U. S. Geol. Survey No. 84, 1892, pp. 105-123. 

« BuU. U. S. Geol. Survey No. 84, 1892, pp. 107 et seq. 



88 GEOLOGY AKD GEOtJND WATERS OF ELORIDA. 

the Hawthorn formation. At the time of the pubHcation of DalVs 
report, the Hawthorn formation was being quarried and had 
aroused considerable interest because of the presence of phosphoric 
acid in the rock. The formation consists of clays, sands, and phos- 
phatic limestones and lies stratigraphically between the limestones 
of the Vicksburg group and the Alum Bluff formation. It is appar- 
ently the stratigraphic equivalent of the Chattahoochee formation 
but differs from it Hthologically and is therefore given a separate 
name. 

Stratigraphic position. — The stratigraphic relation of the Hawthorn 
formation to the underlying Vicksbm*g group has been observed at 
several localities in the interior of the peninsula. It is believed that 
the deposition of the Vicksburg group was followed by widespread 
emergence, which permitted extensive erosion and the formation of 
hills and valleys. There is no doubt that such emergence and 
consequent erosion affected the central part of the peninsula, where 
the Hawthorn formation is well exposed, for this formation rests 
unconformably upon either the Ocala or the ''Peninsular'' limestone. 
This relation is emphasized by the lithologic character of the beds, 
there being an abrupt change from the soft fine-grained limestones 
of the Vicksbm-g group to the clays, sands, and phosphatic lime- 
stones of the Hawthorn formation. 

At numerous points in the peninsula of Florida the Hawthorn 
formation is found resting unconformably upon limestone of Vicks- 
burg age, and in the vicinity of Hawthorn thin beds of conglomer- 
ate occur in the base of the group. At many of the phosphate 
mines in central Florida the limestones of the Hawthorn formation 
are found overlying either the Ocala limestone or the ''Peninsular" 
limestone with an apparent unconformity which has permitted 
the deposition of sands and some limestone beds along channels 
developed in the upper surface of the Vicksburg formations. It 
should be said, however, that in many of these places the materials 
belonging to the Hawthorn formation appear to have been more 
or less distiu*bed since their deposition, and it is possible that at 
some localities the apparent unconformity may be due to the falling 
of the roof of caverns developed near the contact of the two forma- 
tions. 

The relation of the Hawthorn formation to the Alum Bluff 
formation has not yet been accurately determined, though, at De 
Leon Springs, Chipola fossils have been found in a marl overlying 
phosphate rock which belongs to this formation. 

The relation of the Hawthorn to the other formations of the 
Apalachicola group is somewhat uncertain, but there is no doubt 
that its deposition was in part contemporaneous with the Tampa 
and Chattahoochee formations. In fact, although the absence of 



GEOLOGY OF NORTHERN AND CENTRAL FLORIDA. 89 

paleontologic information makes it impossible to correlate these 
formations on biologic grounds, there is no doubt that they were all 
deposited during an extensive submergence which succeeded the 
emergence of the rocks belonging to the Vicksburg group. On 
physical grounds, therefore, there is good reason for regarding these 
formations as synchronous. 

Lithologic character. — At the request of Mr. Vaughan the type 
locality of the Hawthorn formation was recently visited by Sellards, 
who reports that the rock is no longer quarried. According to 
Sellards, the rock is a light-colored, soft, porous limestone. The 
original building-stone quarry near Grove Park station, about 3 
miles west of Hawthorn, is badly overgrown, so that the thickness 
of the limestone can not be determined. At the old phosphate 
mine, which is at least a mile southwest of the stone quarry, the 
rock is a phosphatic conglomerate. 

At many localities the limestones of the Hawthorn formation are 
silicified, forming bowlders and beds of chert. (See PL IX, p. 80.) 
This is a very common condition in the rock-phosphate region, where 
these limestones rest directly on those belonging to the Vicksburg 
group. (See PL X, p. 94.) Beneath the phosphatic limestones of 
the Hawthorn formation at some localities are beds of sand, sandstone, 
or gravel, which are underlain by several feet of clay. The sand 
beds contain iron oxide, which forms a coating on the grains of silica. 
The clays are greenish and locally are sufficiently calcareous to be 
called marls. 

TJiicTcness. — The thickness of the Hawthorn formation varies 
greatly, in places aggregating approximately 95 feet. The three 
members of this formation with their maximum observed thick- 
nesses, according to Dall,^ consist of greenish clay 70 feet, ferrugi- 
nous yellow sandstone 4 feet, and phosphate rock 20 feet. The 
maximum thickness of the Hawthorn formation, as given by the 
same author, is 125 feet.^ However, over a large part of the penin- 
sula, where the sole representative of the Hawthorn formation is 
the phosphatic or siliceous rock, the thickness is but a few feet. 

PJiysiograpJiic expression. — ^The Hawthorn formation in few 
places has much influence on the surface configuration of the region 
which it underlies. LocaUy, however, the cherty beds protect the 
imderlying rock from erosion and thus give rise to ridges, and 
where the clays lie near the surface they are characterized by an 
erosion surface of moderate relief. Most of the cherfc-capped ridges 
are inconspicuous, but in some parts of the phosphate region they 
form distinct topographic features. 

Paleontologic cJiaracter. — ^The fauna of the Hawthorn formation 
has received but little attention and is practically unknown. The 

1 BuU. U. S. Geol. Survey No. 84, 1892, p. 109. 2 Idem, p. 158. 



90 GEOLOGY AND GEOUND WATEES OF FLOEIDA. 

green clay and sands are reported to contain many thoroughly silici- 
fied oyster shells, and the phosphatic limestones and the chert beds 
are characterized by numerous specimens of an echinoid belonging 
to the genus Cassidulus. MoUuscan remains are associated with this 
echinoid, but they have not yet been studied. 

Structure. — ^The Hawthorn formation has been affected by the 
broad earth movements which produced the peninsula of Florida. 
It has a gentle seaward dip, noticeable in few single exposures but 
determinable by means of well records, which show that it sinks 
below sea level on the east coast. The strata probably incline both 
northward and southward from the central part of the peninsula, 
but the determination of the degree of dip requires more detailed 
study than has yet been made. The general easterly dips are known 
to be irregular in amount but probably do not average as much as 
75 feet to the mile, and the dips in other directions may be less 
steep. 

Areal distribution. — ^Although the Hawthorn formation is well 
known, detailed sections are comparatively few. The most com- 
plete sections which have been recognized as belonging to this forma- 
tion are those described by Dall.^ At the type locality near Haw- 
thorn the rock is phosphatic and has been mined and crushed for 
use as a fertilizer, and at many other places it contains more or less 
phosphate. One of these localities is at the Devils Mill Hopper, 
northwest of Gainesville, where the rock is exposed in the walls of 
the sink, which has a depth of about 115 feet. Here the greater 
portion of the section belongs to the Vicksburg group, but a phos- 
phatic rock near the top probably represents the Hawthorn forma- 
tion. Another sink which exposes this formation (sec. 18, T. 7 S., 
K. 18 E.) is described by Dall ^ as follows: 

This place is locally known as "Nigger Sink," and the Vicksburg limestone has 
been reached by a well hole in the center of it. Above the well the lower 10 feet of 
the wall of the sink is hidden by talus, but is believed to be clay of a greenish-yellow 
color, 30 feet of which rises above the talus, covered by a 4-foot layer of firm, hard 
sand, almost a sandstone, and this by a sandy ferruginous layer of clay and gravel 
containing an oyster, like 0. virginica, reproduced in chalcedony. This ferruginous 
layer, which will be referred to here under the term ferruginous gravel, seems to 
appear in many different sections, with its oyster and silicified corals. It also occurs 
in Georgia. Above it is a layer 2 feet thick of soft sandstone resembling the phosphatic 
rock in appearance. Covering this is a bed of sand and clay 8 feet thick, containing 
fragments of all sizes from a few pounds to a ton in weight, of the phosphatic rock 
and its large siUcified coral heads. These last, when they appear on the surface as 
around Archer, from the solution of the phosphatic matrix are popularly known as 
''fossil stumps" or ''nigger heads." They are large masses of chert or chalcedony, 
often hollow, retaining on the surface more or less obscure indications of the original 
coral structure. Above this stratum come the surface sand and loam, here about 20 
feet thick. 

1 BuU. U. S. Geol. Survey No. 84, 1892, pp. 107-112. 2 Idem, p. 109. 



GEOLOGY OF NORTHEEN AND CENTRAL FLORIDA. 91 

In this sink a well was drilled to limestone of the Vicksburg group, 
but the depth and character of the material penetrated is not given. 
The same writer gives more or less complete descriptions of several 
other sections. One of these is at Newnansville, where the clay 
which immediately overlies limestone of the Vicksburg group has a 
thickness of 70 feet and is overlain by 2 feet of ferruginous sand, 3 
feet of undescribed material, and 8 to 20 feet of phosphatic rock. 
About 5 miles east of Mixons the ferruginous sand rests on the Vicks- 
burg group and is overlain by the phosphatic bed, and nearer Archer 
the remnants of the phosphatic rock are found resting directly upon 
the Vicksburg. Occurrences of similar phosphatic rock are reported 
where the railroad crosses Hillsboro Kiver and at Jarves Springs,, 
and at De Leon Springs a phosphatic rock is said to be overlain by 
beds containing Chipola fossils. The same phosphatic rock is also 
reported from Live Oak and Lake City, and the ferruginous bed with 
its silicified oysters is known to occur at Levyville and at Magnesia 
Springs. The following sections are given and described by Dall : ^ 

Section at White Springs on Suwannee River. 

Feet. 

I. Gray eoil, sand, and humus 2 

II. Whitesand 4 

III, Clay with sihcified corals and oyster (Hawthorne beds) 6-8 

IV. Indurated clayey rock (Hawthorne beds?) 2 

V. Clayey sandrock, rather fine grained and soft 4 

VI. The same, somewhat coarser and harder 8-10 

VII. Sandrock of coarser sharp grains, coated and cemented to- 
gether with white limy matter 4-6 

VIII. Foraminiferal Eocene top rock (Vicksburg) indefinitely 
below. 
The silicified corals of bed III are sometimes 20-60 pounds in weight, and along the 
river when dislodged from the clay often wear immense potholes in the softer lime- 
rocks. Miocene sharks' teeth and fragments of bone also occur in the clay. Under 
bed VIII, when it is tilted up, as occurs in various places along the river, is found 
the older Orhitoides limestone of the Vicksburg group. 

Section in sink 4 miles north of Lake City. 

Feet. 

I, II. Sand and sandy soil 5 

IV. Indurated clayey rock 2 

VII. Lime-cemented sandrock 8 

VIII. Foraminiferal Eocene (indefinitely down). 

At White Springs numerous specimens of Cassidulus were obtained 
from a cherty rock which had been used in constructing a foundation 
for the spring house. According to reports obtained from well- 
informed residents of the town this rock was quarried from the river 
channel. At the time of the field investigations for this report the 

1 Op. cit., pp. 110-411. 



92 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

river was too high to permit examination of the outcrop, but subse- 
quent examination by Stephenson ^ resulted in finding the cherty 
beds of the Hawthorn formation in close proximity to exposures of 
the Alum Bluff formation. This strengthens the conclusion that 
was formed at the time of the earlier field work — -that the Cassidulus- 
bearing zone lies near the top of the Hawthorn formation. 
Dall ^ gives this section: 

Section 2 miles south of Lake City. 

Feet. 

I. Sandy soil 2 

III. Clay, with corals and oysters 20 

VII. Lime-cemented sandrock 3 

VIII. Foraminiferal Eocene (indefinitely below). 

Near the southern boundary of Columbia County, at Fort White, the rocks are gently 
folded and the surface has been more or less worn into basins containing phosphatic 
breccia of the older limerocks, which are themselves under these basins of phosphate 
slightly phosphatized in their upper portions. Here, owing to the fact that the Mio- 
cene and Foraminiferal Eocene (Miliolite) beds have been more or less broken up by 
the action of water dissolving or wearing away the softer parts, the Orbitoides lime- 
stone sometimes immediately underlies the breccia in the basins, and in other places 
the basins are composed of the Miliolite limestone. Beds VI, VII, and VIII of the 
above series are more or less silicified, or when broken up the resulting breccia con- 
tains numerous angular fragments of chert. 

In the north-central part of the peninsula and extending as far 
south as Croom many exposures of chert and cherty limestone rest 
on the limestone of the Vicksburg group. Most of this rock contains 
many casts and molds of an echinoid, which Vaughan has identified 
as a Cassidulus. The rock appears to be very persistent but in few 
places attains any great thickness. At Bass station, about 6 miles 
southwest of Lake City, it was quarried to a depth of 12 or 15 feet 
without reaching the underlying Vicksburg group. About 6 miles 
west of Gainesville, on the Newberry road, it appears to have a thick- 
ness of more than 15 feet and to rest directly on the Ocala limestone, 
which forms the country rock of that region. The same echinoid 
is found in cherty beds in many localities between Bass station and 
High Springs and at Alachua sink. White Springs, EllavUle, and 
Croom, and at numerous localities in the hard rock phosphate region. 

At the railroad trestle just west of White Springs sands, marls, and 
clay, probably the local equivalent of the limestones of the Haw- 
thorn formation, are exposed passing under the Chipola marl mem- 
ber of the Alum Bluff formation. A section at the railroad trestle 
shows the following materials : 

1 Stephenson, L. W., unpublished notes. 

8 5ull. U. S. Geol. Survey No. 84, 1892, pp. 110-111. 



GEOLOGY OF NOETHEBN AND CENTRAL FLOEIDA. 93 

Section at railroad trestle just west of White Springs. 

Feet. 

Loam, sandy 20 

Marl, soft, friable, containing some bands of chert and numerous 

echinoids 10-15 

Marl, soft, containing oyster shells 1 

Clay, light green, thinly laminated, siliceous 4 

Sand, light green; to w'ater 4 

44 

CHATTAHOOCHEE FORMATION. 

Nomenclature. — The limestones and marls exposed along Apa- 
lachicola River have been differently grouped by different writers. 
In this paper the name Chattahoochee formation is restricted to 
those limestones and marls of north and west Florida which lie 
stratigraphically between the limestones of the Vicksburg group and 
the Chipola marl member of the Alum Bluff formation. Beds of 
chert occur in this formation and thin layers of sand and clay are not 
uncommon. The type locality is at new Chattahoochee Landing, 
where there is a small exposure of light-gray marl and impure lime- 
stone. This formation is a ,part of Langdon's^ Chattahoochee 
group, and it is apparently the Chattahoochee group of'Foerste.^ In 
1892 Dall ^ called it the Ocheesee beds, but in a subsequent paper 
he notes the absence of exposures at Ocheesee * and uses the names 
Chattahoochee fornaation^ and Chattahoochee limestone.^ As the 
formation contains considerable marl, the use of Chattahoochee 
limestone is not entirely satisfactory, and hence the name Chatta- 
hoochee formation is retained. 

StratigrapJiic position. — The Chattahoochee formation is known to 
rest unconformably on the underlying limestone of the Vicksburg 
group in southern Georgia. The evidence of the unconformity was 
summarized in 1893 by Pumpelly,^ who states that there is usually 
a limestone conglomerate at the base of the Chattahoochee forma- 
tion in southwestern Georgia and that the altitude of the contact 
between the two limestones varies considerably in short distances. 
The variations in altitude given by Pumpelly might, if considered 
alone, be regarded as due to deformation rather than to erosional 
unconformity, but the evidence of erosion is strongly supported by 

1 Some Florida Miocene: Am. Jour. Sci., 3d ser., vol. 38, 1889, pp. 322-324. 

«Am. Jour. Sci., 3d sen, vol. 48, 1894, pp. 41-54. 

8 Bull. U. S. Geol. Survey No. 84, 1892, p. 87. 

* Dall, W. H., and Stanley-Brown, Joseph, Cenozoic geology along Apalachicola River: Bull. Geol. Soc. 
America, vol. 5, 1894, p. 154. - 

6 Idem, p. 152. 

8 Idem, p. 155. 

' Pumpelly, Raphael^ An apparent time break between the Eocene and Chattahoochee Miocene in south- 
western Georgia: Am. Jour. Sci., 3d ser., vol. 46, 1893, pp. 445-448. Also Vaughan, T. W., A Tertiary 
coral reef near Bainbridge, Ga.: Science, new ser., vol. 12, 1900, pp. 873-875, 



94 GEOLOGY AKD GEOUND WATERS OF FLORIDA. 

the conglomerate, which in some places resembles breccia but in 
others contains rounded pebbles of the underlying rock. The differ- 
ence in lithologic character between the limestones of the Vicksburg 
group and the limestones of the Chattahoochee formation is so marked 
that it would hardly be possible to mistake the source of these peb- 
bles. The probability that the inequalities of the surface of the 
limestones of the Vicksburg group are due to erosion is strengthened 
by the paleontologic evidence. On evidence furnished by Foerste, 
Pumpelly states that the Chattahoochee at Griffins Creek contains 
a fauna characteristic of the upper part of the formation and in other 
localities examined contains faunas ^belonging to the lower part. It 
thus appears that at Griffins Creek deposition did not begin until 
after the formation of the beds exposed in the immediate neighbor- 
hood; or, in other words, that an island consisting of the underlying 
limestone of the Vicksburg group was not submerged until after the 
deposition of the lower part of the Chattahoochee formation. 

Tuomey also collected corals at the contact between the Chatta- 
hoochee and the underlying limestones, and Dall identffied these as 
belonging to the base of the Miocene,, to which the members of the 
Apalachicola group were formerly assigned. 

In Florida the base of the Chattahoochee formation was not seen, 
but there is little doubt that its relation to the limestones of the 
Vicksburg group is similar to that in Georgia. This view is strength- 
ened by what is already known of the physical history of the State 
and by the fact that both the Hawthorn and Tampa formations, 
which appear to have been deposited at about the same time as the 
Chattahoochee, rest upon the eroded surface of the limestones of the 
Vicksburg group. 

Lithologic character. — The Chattahoochee formation consists of 
light-colored limestones and marls, containing some thin beds of 
chert, clay, and sand. The colors vary from creamy white to light 
gray or green on recently exposed surfaces to light yellow-brown or 
more rarely pink on weathered outcrops. Lithologically, there is a 
gradation from nearly pure limestone to sands and clays, but in 
general the argillaceous and siliceous limestones predominate, form- 
ing marls. The formation is in part composed of semicrystalline 
limestone (PL X, B), but soft, loosely coherent rock resembling an 
impure chalk is more common. Chert beds occur at various horizons, 
but they are much thinner and less persistent than in the underlying 
Vicksburg group. At times organic life appears to have been abun- 
dant, some layers being very fossiliferous; the fossils are usually pre- 
served in the form of imperfect casts and molds which have been left 
by the solution of the shells. 



U. S. GEOLOGICAL SURVEY 



WATER-SUPPLY PAPER 319 PLATE X 




A. LIMESTONE OF TAMPA FORMATION EXPOSED ALONG SIXMILE CREEK A QUARTER OF 
A MILE BELOW ATLANTIC COAST LINE RAILWAY BRIDGE, HILLSBOROUGH COUNTY. 




B. LIMESTONE OF CHATTAHOOCHEE FORMATION ON WITHLACOOCHEE RIVER AT NEW BRIDGE 
(OR HORN BRIDGE), 3 MILES BELOW GEORGIA & FLORIDA RAILWAY BRIDGE, LOWNDES 
COUNTY, GA. 



GEOLOGY OF NOKTHERN AND CENTRAL FLORIDA. 95 

Thickness. — Vaughan's ^ observations along Apalachicola River 
show that the Chattahoochee formation attains considerable thick- 
ness near the type locality. He says: 

The Chattahoochee limestone at the Old Landing has a thickness of at least 85 
feet and probably more, for the basal 20 feet of the two sections measured on the roads 
to the water's edge at the river is not exposed. However, in all probability the 
alluvium bottom accompanying the river is underlain by this formation, giving 
it a total thickness of slightly more than 100 feet. 

Well borings from Quincy indicate that the thickness of the Chat- 
tahoochee formation at that locality is slightly greater than 100 feet; 
but here, as elsewhere, it is difficult to determine the exact thickness 
of formations from well samples. The maximum thickness is prob- 
ably 200 feet and may even be as great as 250 feet. 

PJiysiograpTiic expression. — In general the region underlain by the 
Chattahoochee formation is one of high relief and well-developed 
surface drainage. However, this is not always due to the character 
of the formation, for in the northern part of the State the surface 
configuration is in many places determined in part by the character 
of superficial sands and clays of late Oligocene and post-Oligocene age. 
The limestones of the Chattahoochee formation are less soluble than 
those of the underlying Vicksburg group, and hence contain fewer 
underground streams and a less characteristic sink-hole topography. 
However, underground streams, sink holes, and natural ridges are 
by no means rare. Where the limestones belonging to the Chatta- 
hoochee formation are thin, the topography is often the combined 
result of solution of the lower Oligocene limestones and the protection 
of the ridges and hills by the more durable upper Oligocene limestones. 

Paleontologic character. — At some localities in southern Georgia the 
basal layers of the Chattahoochee formation are rich in corals.^ The 
lower part of the formation contains Orthaulax pugnax, a gastropod 
characteristic of the ^'silex bed" at Tampa. This locality has been 
studied by Vaughan,^ whose description emphasizes the existence of 
an erosion interval between the deposition of the Vicksburg and the 
Apalachicola groups, and shows the existence of fossil coral reefs. Of 
this coral reef, Vaughan says: 

My estimate is that there are between 25 and 30 species. 

This is the richest fossil coral fauna known from any one locality of the continental 
North American Tertiaries. However, the state of preservation of the specimens 
is not always satisfactory, and it may not be possible specifically to describe all of them. 

The particular interest of this fauna does not lie in its richness but in its geologic 
import. The Tertiary coral faunas of the United States below the Chipola horizon 
were very isolated, no species from the continent, excepting the Orbicella mentioned, 
being found in any other area. This fauna is distinctly Antiguan in types. Besides 

1 Vaughan, T. W., unpublished notes. 

* Pumpelly , Raphael, An apparent time break between the Eocene and Chattahoochee Miocene in south- 
western Georgia: Am, Jour. Sci., 3d ser., vol. 46, 1893, pp. 445-447. 
' Vaughan, T. W., A Tertiary coral reef near Bainbridge, Ga.: Science, new ser., vol. 12, 1900, pp. 873-875, 

76854°— wsp 319—13 7 



96 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

the Orbicella referred to, there is a very large celled Orbicella, very close to 0. crassi- 
lamellata (Duncan), if not identical with that species, found abundantly at Russell 
Spring. An Astrocoenia is extremely close to A. ornata of Duncan from Antigua. 
The same remark will apply to the Stylophora and Alveopora. 

From this field examination it appears that the reef corals of the Antiguan marls 
and cherts can be correlated with the base of the Chattahoochee limestone, the base 
of Dall's Upper Oligocene. It is also quite probable that the Oligocene reefs in the 
vicinity of Lares, Porto Rico, and of Serro Colorado, Curacao, represent the same 
horizon. The Bowden, Jamaica, fauna would be slightly higher, to be correlated 
with the Chipola fauna. 

It is evident that this coral fauna from Russell Spring, besides filling a gap in the 
faunal succession on the continent, furnishes a basis for correlating many of the West 
Indian fossil reefs with the continental Tertiary section, and we may confidently 
expect more light upon the correlation of American and European horizons. 

One interesting feature of these corals, not already mentioned, is that they appar- 
ently bring the fauna of Vicksburg, Miss., into closer relations with the succeeding 
faunas. A great deal is shown regarding the succession and interrelations of the 
faunas of the continent itself. 

A bed in the lower part of the Chattahoochee formation in most 
places contains an abundance of echinoids, and several different 
genera belonging to this group are known to occur at other horizons. 
About 20 feet above the echinoid bed there is a layer containing an 
abundance of gastropods belonging to the genus HeUx; a slightly 
higher layer is characterized by numerous specimens of Cerithium. 

Structure. — In northwestern Florida the limestones of the Chat- 
tahoochee formation dip toward the south. The exact amount of 
this dip is difficult to determine, but careful estimates by Miss Maury ^ 
place the average descent at 23 feet per mile. The same writer has 
noted a variation in the rate of dip; she says: 

That this dip is steeper toward the north is shown by the following rate of slope: 
Aspalaga to the ravine, one-eighth mile, 10 feet, or 80 feet per mile; Aspalaga to 
Camp Scott, 2 miles, 70 feet, or 35 feet per mile; Camp Scott to Rock Bluff, 3 miles, 
48 feet, or 16 feet per mile. 

Areal distribution. — The Chattahoochee formation, which is best 
exposed along Apalachicola River, has been described by a number of 
writers. According to Ball the major portion of the rock exposed 
at Chattahoochee belongs to the Alum Bluff formation. His most 
complete sections are given below: ^ 

Section on road running northeast from old Chattahoochee Landing. 

Feet. 

1. Reddish sand and gravel, with streaks of clay. 20 ^0 

2. Grayish yellow friable marl, with harder layers 20 

3. Greenish clayey marl, very adhesive 2^ 

4. Chattahoochee limestone, with fossil casts 4 

5. Talus to water's edge, about 3 

1 Maury, C. J., Bull. Am. Paleontology, vol. 3, No. 15, 1899-1902, p. 58. 

2 Dall, W. H., and Stanley-Brown, Joseph, Cenozoic geology along the Apalachicola River: Bull. Geol. 
Soc. America, vol. 5, 1894, p. 152. 



GEOLOGY OF :N0ETHERN AND CENTRAL FLORIDA. 97 

Section on road running southeast from old Chattahoochee Landing. 

Feet. 

1. Reddish sands, gravel, and clays 15 -20 

2. Grayish yellow marl, friable 20 

3. Greenish clayey marl, sticky 2^ 

4. Talus to water's edge, about 3 



30^^5^ 
Dall says: 

Section No. 2 was taken on the road which runs about southeast from the landing. 
The exposures are mostly in the gullies. The fossil-bearing bed is No. 4 and con- 
tains, among other fossils, echinoids, Pecten (Chipolasp.), Area (like transversa), large 
solitary coral, Venus penita, Lima (like scdbra), Hemicardium, Ostrea, Loripes, Scala, 
Plicatula, Divaricella, Pyrazisinus, Phorus, all as poor casts; fish bones and ribs of some 
mammal resembling those of the manatee. No orbitolites were seen. 

From the correlations made by Dall it is apparent that he regarded 
No. 1 of the above section as Lafayette and Nos. 2 and 3 as Alum 
Bluff. A generalized section made by Vaughan from old Chatta- 
hoochee Landing to Chattahoochee post office is given below: 

Generalized section from old Chattahoochee Landing to Chattahoochee post office. 

Feet. 

3. Red sands with some gravel, toward base becoming more argilla- 
ceous; in places composed of mottled red sands and bluish or pur- 
plish clays. The basal portion forms a mantle following rather 
closely the contact with the Alum Bluff formation. The mottled 
basal portion extends through a vertical distance of about 40 f eet . . . 50 

2. White chalk and clays, in places greenish or bluish. The greater 
portion of these clays is calcareous and a considerable portion is 
argillaceous limestone in harder and softer ledges. A calcareous 
specimen (chalky) was taken 70 feet above the water's edge of the 
river. The clays are jointed and show conchoidal exfoliation. The 
lower portion of this exposure does not appear to be calcareous. 
Some fine sands at the bottom. (Rocks of the same character, 
either clay or limestone, occur 100 feet above the river. The total 
thickness of the Chattahoochee formation here exposed is 80 feet. ) . 50 

1. Alluvium of river bottom composed of reddish sands along the 
river. No exposure of beds beneath the river alluvium was seen . . 20 

120 

In commenting on this section, Vaughan says : 

It is evident that I did not examine the specific locality described by Dall, for I 
did not see his Chattahoochee Limestone. The upper part of his No. 2 is the lower 
part of my No. 2. From Ball's description, the whole of my No. 2 would be referable 
to the Alum Bluff. The combination of his section and mine give a thickness of over 
80 feet. His maximum thickness is 67 feet. 



98 GEOLOGY AND GKOUKD WATERS OF FLORIDA. 

The following more detailed section by Vaughan shows the character 
of the rocks exposed in the lower part of the section given above: 

Detailed character of lower part of section given above. 

Feet. 

White argillaceous chalk in harder and softer layers 46 

Very calcareous blue clay 2 

Indurated calcareous clay, stained yellow in places 15| 

Six feet six inches above the base are fine-grained, very calcareous 
marls, white or slightly tinged with yellow in spots. This stratum 

contains casts of many shells, etc. 

631 

At Wileys Landing on Chattahoochee River, about 7 miles above 
Eiver Junction, Vaughan obtained a section given below, but it has 
not been correlated with the other sections farther down the river : 

Section of bluff at Wileys Landing. 

Feet. 

Red clay 5- 6 

Limestone 25 

Not definitely exposed, clay or limestone, probably limestone or 

calcareous clay 5^ 

Limestone containing a large oyster, Isocardia, Venus, Pyrula, etc . . 5| 

Unexposed surface red clay, apparently underlain by limestone . . 11 

Bluish sticky clay 5^ 

From water's edge to 5 feet 6 inches not definitely exposed, but 
apparently bluish sticky clay. There is much limestone 
detritus over the surface, it having rolled down from the upper 
part of the bluff 5^ 

The surface of this bluff is so covered by red clay and talus from above (limestone 
pebbles and bowlders) that it is not possible to discover the details of the section. 
The basal 11 feet are argillaceous, while the succeeding 47 feet are for the most part 
limestone. But the rock is so indurated that the fossils can scarcely be freed from the 
matrix. In one portion of the limestone horizon, the lower 25 feet, very large oyster 
shells are abundant. These weather out in good condition, probably because their 
matrix is argillaceous or because the limestone is softer. The greater portion of the 
limestone is hard and rings under blows of the hammer. 

No fossils were found in the basal argillaceous layers. These lower layers would ^ 
according to the literature, probably be referred to the Vicksburg. The limestone 
belongs to the Chattahoochee. The lithologic specimen of it was taken from the top 
of the exposure and a fair number of fossils were collected. The exposure was also 
photographed. This section was measured by a hand level. 

The following descriptions were also furnished by Vaughan : 

Section at Aspalaga Landing. 

Feet. 

5. Sand : 27§ 

4. White limerock. The surface appearance and color are those of 
chalk. This rock is indurated in thick, massive ledges, and 
fragments show concentric exfoliation. Its color is originally 
bluish and becomes white upon drying 39| 

3. Chalky limestone, more calcareous in the basal portion 18-20 



GEOLOGY OF NOKTHEEK AND CENTRAL FLORIDA. 99 

Feet. 
2. Friable limestone, containing patches of blue clay and very- 
poor remains of fossil mollusks IJ 

1. Whitish chalk, tinged yellowish, which when kneaded in the 
water forms a whitish sticky paste. The stratum is suffi- 
ciently indurated to form a ledge and extends at least 1 foot 

below the surface of the water 7f 

The argillaceous basal portion of stratum No. 3 is about 2 feet, then follows a chalky 
stratum and bluish clays at the base of No. 4. 

At the extreme upper end of the bluff the exposure is more satisfactory. The bluff 
face (Nos. 1, 2, and 3, and the lower 10 feet 8 inches of No. 4, total thickness 30 feet 5 
inches) is white chalk with layers of more or less friable and argillaceous marl. Fos- 
sils are very numerous in several layers of the chalk, especially in stratum No. 2 and 
at the top of the bluff face, but all are miserably preserved, there being no shell sub- 
stance left, only casts. Nucula, Pecten, Venericardia, Lucina, Isocardia, Meretrix, 
Turritella, Stylophora, solitary corals, etc., were observed. 
A resume of the exposure at Aspalaga, excluding the surface sands, is as follows: 

Resume of section at Aspalaga landing. 

Feet. 

Stratum 4 39^ 

Stratum 3 11 

Stratum 2 IJ 

Stratum 1 7| 

The whole of these 59J feet (perhaps excepting some marl beds near the top) is 
chalky limestone. This section was measured with a hand level. 

I could not find the marl bed described by Dall and think it must have been a 
disintegrated chalky stratum or weathered chalk, as the weathered chalk is frequently 
a clay marl. The limestone was sectioned at two places, one near the lower end of the 
bluff; the measurements were by hand level and steel tape; the uppermost exposure 
was a ledge and the thickness, as has already been stated, was 59 feet 6 inches, or 
roughly, 60 feet. 

Near the upper end of the bluff an aneroid section was made and 55 feet was the 
thickness by that measurement, practically the same as the preceding. 

Coming down the road to Aspalaga landing is an exposure just before passing to 
the river bottom. To the right of the road is a small branch that empties into the 
Apalachicola at Aspalaga landing. The Chattahoochee formation forms an escarp- 
ment a few feet high along the northern side of the branch. An aneroid measurement 
from the water's edge to the highest exposure on the road gave a thickness of 35 feet; 
that is, only a portion of the limestone is there exposed. 

At the crossing of the River Junction-Bristol road (over Flat Creek) is an exposure 
of limestone of small extent, probably the Chattahoochee. 

Tests with acid of specimens from Aspalaga Bluff. 

Stratum 4. Specimen from highest exposure effervesces. 

Specimen from chalk ledge in face of bluff, effervesces. 
Stratum 3. Clay, just beneath base of No. 4, considerable effervescence. 

Very calcareous, stiff blue clay, effervesces strongly. 
Stratum 2. A friable limestone, containing considerable clay. 
Stratum 1. Is an argillaceous limestone, chalk. 



100 GEOLOGY AND GROUND WATERS OE FLORIDA. 

Section at western end of trestle east of River Junction, milepost 206. 

Feet. 

(7) 4. Soil and humus 1. 5 

(6) 3. Gray sands 3 

(5) 2. Stiff mottled sandy clay 3 

(4) 1. Stiff noncalcareous blue clay 3. 2 

Section measured with steel tape. 

Section immediately below (4) 1 of the preceding section and nearer the creeh. 

3. Sandy ferruginous clays, containing black, apparently carbona- 

ceous particles. Stratum mottled yellowish or brown, and Feet, 
bluish white with black spots. 3 

2. Stiff blue clay with lumps or seams of white clay 1 

1. White sandy noncalcareous clay, oxidizing yellowish or brown 

on surface 3^ 

The barometer readings correlate these clays in altitude with those immediately 
back of the station house at River Junction, and as they are similar in character this 
correlation is apparently trustworthy. 

One telegraph pole west of milepost 205 is an exposure of the argillaceous chalk of the 
Chattahoochee 2.7 feet in thickness. It is overlain by the dump from the railroad 
excavation. The material was tested with acid and found to be calcareous. It has 
the appearance of the usual limestone of the Chattahoochee. The surface shows 
irregular joints and conchoidal or concentric exfoliation. One imperfect fossil was 
found, a surface cast, probably a Lucina. 

This locality is about 2^ miles east of River Junction railroad station on the Seaboard 
Air Line Railway. River Junction is at milepost 208, 208 miles from Jacksonville. 

From looking along the railroad this exposure seems to be topographically lower than 
the two preceding exposures. 

Excepting the two exposures described, there are none between this locality and 
River Junction excepting surficial sands and maybe some red sands or clays and sands. 
There are no deep cuttings along the railroad track. 

Section at station house, River Junction. 

Feet. 

Chocolate-colored or brownish soil 1 

Sandy whitish clay 1^ 

Sandy whitish clay slightly calcareous in ledges 8 

Section near lower end of train yard. 

Feet. 

7. Humus and blackish or dark-brown soil, about 1 

6. Yellow sandy clay or marl, estimated 3 

5. Whitish sandy clay very slightly calcareous 4.7 

4. Whitish sandy clay (very slightly or not at all calcareous) 4 

3. More calcareous white sandy clay 1 

2. Very calcareous sandy clay 1. 5 

1. Sandy chalk, very argillaceous; sand grains fine 6. 5 

2L7 
No. 1 at edge of sand flat of small branch. This last bed is the one from which Dall 
mentioned fossils. I found as poor casts Isocardia, Hemicardium, Venericardia, 
Tagelus, Turritella (very large species), cast of inside of large gastropod (Orthaulax?), 
smaller gastropods, etc. There were many specimens and many species, all poorly 
preserved. 

Between River Junction and the railroad bridge over Apalachicola River there are 
no rock exposures except the one already mentioned. 



GEOLOGY OF NOKTHERN AND CENTRAL FLORIDA. 101 

A number of fossils were obtained by Vaughan at a small fall in a 
ditch running east from the back of the station house at River 
Junction. A list follows: 



Mammalian ribs, fragments. (These ribs 
are probably of the manatee.) 

Large cheliped crustacean claws, the 
animal apparently the size of a large 
lobster. 

Cardium, several species. 

Hemicardium. 

Venericardia. 



Pecten. 

Venus. 

Lucina. 

Astarte. 

Natica (very large species). 

Orthaulax?. 

Fusus. 

Cerithium or Turritella. 



The shells are all casts, internal or external, but the fauna is evidently typical 
Chattahoochee. One fine regular echinoid was collected. 

Cement quarry one-half mile south of River Junction. 

Feet. 
Superficial coating of black humus and some gray sand. 

Friable chalky limestone, forming slope of hill 13 

Harder chalky layer 5 

Softer chalky layer 1. 5 

Harder, somewhat saccharoidal limestone 9 

Softer fossiliferous chalk 1. 7 

Harder limestone with numerous fossils, the commonest being 
Hemicardium and an orbitoid foraminifer. This material when 
weathered turns reddish and forms a residual red clay. No orig- 
inal molluscan tests were observed, but they are sometimes re- 
placed by crystalline calcite 1. 3 

Soft white chalk, indurating upon exposure, used in making cement 
brick. (Base, by barometer, 50 feet above the railroad at River 
Junction) 4 

Some 12 to 15 feet of limestone belonging to the Chattahoochee 
formation is exposed at Rock Bluff and it doubtless underlies the 
Chipola marl member at Alum Bluff. On Chipola River the same 
limestone is exposed at intervals from near the mouth of Tenmile 
Creek northward to beyond Peacock Bridge. Few of these exposures 
exceed 4 or 5 feet in thickness and the rock is a chalky limestone 
similar to that exposed on Apalachicola River. The outcrops at 
Peacock and Willis bridges on Chipola River were visited, but they 
proved to be nearly destitute of organic remains. This limestone 
doubtless forms the natural bridges over TenmUe and Sinking creeks, 
tributaries of Chipola River, but high water prevented a close exam- 
ination of the localities. Similar limestone occurs in the form of 
loose bowlders in the vicinity of Knoxhill, Walton County, and 
outcrops of it are reported on Choctawhatchee River, south of the 
Louisville & Nashville Railroad bridge. At Caryville the well of 
the Wood Lumber Co. penetrated 8 feet of pinkish limestone, which 
doubtless belongs to the Chattahoochee formation. The limestone 
at St. Marks and at some localities farther north and east is also 
tentatively referred to this formation. 



102 GEOLOGY AND GKOUND WATERS OF PLOEIDA. 



TAMPA FORMATION. 



Oharacter and nomenclature. — The Tampa formation consists of 
greenish, clays, light gray to yellow limestones, and a very f ossilif erous 
bed of ^^silex." Hitherto, the '^silex" and a portion of the limestone 
has been all that was known of the formation. The ''silex bed" 
and limestone of the Tampa formation were first examined by 
Conrad ^ more than 60 years ago. In the same year Prof. Allen ^ 
described both the limestone and ^'silex bed" at Tampa, and his 
account of these beds has been generally accepted as correct. The 
same locality was subsequently visited by Tuomey.^ In 1884 Kerr 
and Mitchell^ visited Tampa and noted the replacement of fossil- 
iferous limestone by chalcedony in what has since been called the 
'^silex bed." Ballast Point, near Tampa, where the '^silex bed" is 
best exposed, is the locality where Bailey ^ found what he regarded 
as infusorial earth resting on the '^silex bed." Later investigations 
have shown this bed to be merely residual material produced by the 
action of the weather on the silicified limestone. 

In 1887 Heilprin ^ published an account of explorations near 
Tampa and called attention to the fact that the fossil which Conrad 
regarded as a nummulite was really an orbitolite. Heilprin gave a 
brief description of Ballast Point and other exposures near Tampa 
but does not appear to have recognized the relations between the 
limestone and the ^'silex bed." Later publications by Dall give 
more complete descriptions of the Tampa exposures and show clearly 
that there are two beds represented, which he called the Tampa silex 
bed (the lowermost) and the Tampa limestone (the uppermost). 
Because the ^^ silex bed" is characterized by the presence of Orthaulax 
pugnax, Dall has called it the Orthaulax bed and the limestone has 
been designated '^Cerithium^ rock" on account of the presence of 
many specimens belonging to that genus. 

In his report on the Neocene of North America, Dall ^ described 
the ''Tampa group," including what he designated the Tampa, 
Chipola, and Alura Bluff beds. But the subsequent discovery of 
Orthaulax pugnax in the Chattahoochee led him to place the ''silex 
beds" in his Chattahoochee group.^ 

1 Conrad, T. A., Observations on Eocene formations and descriptions of 105 new fossils of that period 
from the vicinity of Vicksburg, Miss.: Proc. Philadelphia Acad. Sci., vol. 3, 1848, pp. 19-27; Am. Jour. 
Sei., 2d ser., vol. 2, 1846, pp. 36-48. 

2 Allen, J. H., Am. Jour. Sci., 2d ser., vol. 2, 1846, pp. 36-48. 

3 Tuomey, M., Notice on the geology of the Florida Keys and the southern coast of Florida: Am. Jour. 
Sci., 2d ser., vol. 11, 1851, pp. 390-394. 

* Mitchell, Elisha, and Kerr, W. C, Scientific Soc, 1884-85, p. 87. 

B Bailey, J. W., Microscopic observatioLs: Smithsonian Contr. to Knowledge, vol. 2, No. 8, lS50,p. 19. 
6 Heilprin, Angelo, Explorations on west coast of Florida: Trans. Wagner Free Inst. Sci., vol. 1, 1887. 
pp. 10 and 11. 
1 Bull. U. S. Geol. Survey No. 84, 1892, pp. 112-113. 

8 Op. cit. 

9 Dall, W. H., Tertiary favma of Florida: Trans. Wagner Free Inst, Sci., vol. 3, pt. 6, 1893, pp. 1564-1565, 



I 



GEOLOGY OF NORTHEKN AND CENTRAL FLORIDA. 103 

Wliile engaged in the field work for this report, the writer obtained 
additional information concerning the rocks at Tampa. Stated 
briefly, the observations revealed the presence of a limestone below 
the ^'silex bed" and the existence of clay beds at both the base and 
top of the formation. The limestone below the '^silex bed" is 
similar to what Dall ^ has called Cerithium rock, and in this connection 
it is interesting to note what he has said concernmg its existence: 

• From these observations it appears that, while the existence of a Cerithium rock 
imder the Orthaulax bed is a priori probable, sufficient evidence of its existence is 
still to be collected, and the rock identified as such by Heilprin may very possibly 
have been a portion of the Tampa limestone. 

Since the publication of the report from which the above quotation 
is taken, a series of wells have been drilled, and the samples which 
were preserved show the presence of the limestone below the silex. 

StratigrapJiic position. — Eyidence of an imconformity at the base 
of the Tampa formation was obtained in drilling wells for the city of 
Tampa. The log of one of these wells (see p. 106) shows that after 
passing through 30 feet of limestone and chert the drill entered a 
blue clay 41 feet thick. The limestone and chert represent the 
limestones and '^ silex bed" of the Tampa formation, and the clay 
appears to belong at the base of that formation. At 200 feet from 
this well, the clay was encountered at about the same depth and was 
said to have a thickness of 64 feet. This variation shows that the 
underlying limestones of the Vicksburg group have an irregular 
^Ifirface which was doubtless produced by erosion. 

The relation of the Tampa formation to the Hawthorn and Chat- 
tahoochee formations has not been observed, but the presence of the 
gastropod Orthaulax pugnax in both the Tampa and Chattahoochee 
formations makes it possible to correlate them, and its stratigraphic 
relation to the Alum Bluff formation is probably similar to that of the 
other two formations mentioned. The post-Oligocene formations, 
which occur in the area where the Tampa formation is known, rest 
unconformably upon it. 

Lithologic character. — The upper member of the section at Tampa 
comprises a well-stratified greenish clay containing some calcareous 
nodules and thin beds of limestone near the base. Scattered through- 
out the clay are many silicified corals, some of them having a diame- 
ter of 2 to 3 feet. Although the collection of corals has not been 
examined, there is little doubt that this clay belongs to the Alum 
Bluff formation. The clay is very plastic and hence is valuable for 
the manufacture of brick. Beneath this clay is the light-gray to 
yellow limestone, which was formerly called the ''Tampa limestone." 
(See PL X, A, p. 94.) The ''silex bed" represents a silicified zone in 
this limestone ; and is therefore a zone of replacement. This is well 

1 BuU. U. S. Geol. Survey No. 84, 1892, p. HQ. 



104 GEOLOGY AKD GROUND WATERS OP FLORIDA. 

shown by some of the fossils, which have been only partly silicified; 
and by the presence of more or less unaltered carbonate of lime in the 
original rock. Small nodules of chert occur at other horizons in the 
Hmestone, and outcrops of the rock are commonly denser and harder 
than exposures in quarries. Locally, the limestone is hard enough 
to make a durable building stone which might be useful in the 
construction of foimdations for buildings. Fossils are abundant in 
some parts of the limestone, but they are largely represented by casts 
and molds, which have been left by the solution of the original shells. 
The ''silex bed" contains numerous fossils which have been wholly 
or partly replaced by chalcedony. Here and elsewhere the action 
of the percolating water has removed the matrix, leaving many 
beautifully preserved pseudomorphs and casts of shells. These fossils 
are commonly composed of chalcedony, which in many specimens 
exhibit the characteristic markings of the original shells. 

Beneath the limestone beds is a greenish clay which commonly 
contains a considerable admixture of sand. This clay is very plastic 
and resembles the clay which overlies the limestone. Judging from 
well records, the deposit is homogeneous, but it is possible that the 
sand contained in the well samples may be derived from thin sand 
partings in the clay bed. 

Thickness. — The information concerning the thickness of the Tampa 
formation is meager, but it is sufficient to fix the maximum thickness 
at more than 130 feet. The clay bed at the top of the formation has 
a known thickness of 15 feet. The limestone between the '^silex 
bed" and the upper clay measures about 40 feet. The thickness of 
the ''silex bed" varies considerably, ranging from about 4 feet to 
more than 10 feet. Beneath the '^silex bed" is a limestone which 
has a known thickness of 6 feet. The clay bed at the base of the 
formation has been penetrated by two wells within 200 feet of each 
other; its thickness was 41 feet in the one and 64 feet in the other. 

PJiysiograpJiic expression. — The area underlain by the Tampa for- 
mation is so near sea level that no marked physiographic featm^es 
can be discerned. The influence of the limestone of the formation 
is seen in the rapids of Hillsboro River; and its solution may 
have produced some of the depressions northeast of Tampa. Aside 
from these minor features, the surface of the formation is not very 
diversified. 

Paleontologic character. — In addition to the characteristic Orthaulax 
pugnax, the '^silex bed" of the TamJ)a formation has furnished a 
very large number of species, including some corals, many species of 
gastropods and pelecypods and a few specimens of Orhitolites jlori- 
danus, which becomes abundant in the overlying limestone. At 
Ballast Point the fauna of the '^silex bed," though largely marine, 
contains many fresh-water shells which were probably supplied from 



GEOLOGY OF NORTHEEN AND CENTRAL FLORIDA. 105 



some lakes or lagoons situated near the shore. The complete list of 
the fossils from the '^silex bed" is given by Dall, who says:^ 

About 49 per cent of the species in the Orthaulax bed are peculiar to it, and very 
few of the more minute forms which should be present in such a fauna are known. 
The relations of the fauna are most intimate with that of the Oligocene beds above it, 
the Orbitolite or Tampa limestone, the Chipola, and the Oak Grove sands. With either 
of these the percentage of species common to both is more than twice as great as with 
any of the beds below, such as the nummulitic, the Peninsular limestone, or the 
Vicksburg. But it must be admitted that the faunas of all these, except the last, are 
very imperfectly known. With the faunas of the horizons above the Oak Grove sands 
there is little in common, though in the tropical waters of the Antilles about 8 per 
cent of the species are believed to survive to the present day. Only about 2.6 per cent 
survive except in tropical waters. 

One of the most interesting features of the fauna is the assembly of land shells, which 
are southern immigrants and have left no survivors on the American continent at the 
present day, though representative species occur to the southward. 

The fauna of the limestone in the Tampa formation contains fewer 
species than that of the '^silex bed/' but the two faunas are closely 
related, as will be seen by the following quotation, which contains 
DalFs comments on the list of fossils from these two beds '? 

Total, 95 species, of which 36 are uncertain specifically, leaving 59 identified, of 
which 37 are common to the silex beds, 10 are peculiar to the Tampa limestone horizon, 
4 are known from the Ocala nummulitic limestone, and 2 appear in the Vicksburgian, 
the Jacksonian, and the Claibornian. One species (and probably more not yet dis- 
criminated) survives into the Chipola and two are believed to persist to the recent 
fauna. 

Structure. — The Tampa formation lies near sea level, and hence it 
is difficult to get sections which show the structure of the beds. 
Apparently the formation is nearly horizontal with a slight seaward 
dip; gentle flexures may exist, but the evidence is still too meager 
to show their existence. 

Areal distribution. — The ''silex bed" of the Tampa formation is 
best exposed at Ballast Point, where it rises only a few feet above 
tide. At this locality, the maximum thickness of the bed is not 
shown. Dall's ^ section at Tampa is : 

Sectionof silex bed" at Tampa. 

Feet. 

Sand, white ^2 

Sand, yellow ^—3 

Breccia (Pliocene) Traces. 

Limestone (Tampa) 10-15 

Silex bed 6-10 

In drilling wells at the Tampa waterworks, between Sixth and 
Seventh avenues, the ''silex bed" was found to have a thickness of 
only 4 feet. Beneath it was a thin bed of limestone, underlain by 

1 Trans. Wagner Free Inst. Sci., vol. 3, pt. 6, 1903, p. 1565. 

2 Idem, p. 1572. 

3 Bull. U. S. Geol. Survey No. 84, 1892, p. 113. 



106 



GEOLOGY AND GEOUND WATERS OF FLORIDA. 



greenish clay, that varied in thickness from 41 to 64 feet. The 
one of these wells follows : 

'Log of well at Tampa waterworks. 




Sand, white (Pleistocene) 

Clay, tough, yellow, residual; no sand 

Limestone, soft; disintegrates readily ("Tampa limestone" of some authors) 

Chert (" Tampa silex bed") 

Limestone, soft; closely resembles No. 3 

Clay, tough, plastic, greenish, sandy (base of the Tampa formation) 

Chert 

Marl, white 

Limestone, soft 

Rock, very light colored, hard 

Limestone, very hard, dark yellow 

Limestone, gray, porous; some water 

Cherty beds 

Limestone, darker 

Rock, gray, porous; water 

Clay, gray, plastic 

Rock, hard, yellow; with chert 

Rock, gray, porous; water-bearing 

Like preceding 



The section from 12 to 77 feet represents the Tampa formation, but 
at this locality the upper clay and a portion of the limestone have 
been removed by erosion. The rest of the section represents the 
Vicksburgian limestones. 

Another well 200 feet away encountered 64 feet of the clay, 
which suggests an unconformity at base of this bed, and this hypothe- 
sis is strengthened by the fact that the rock immediately below the 
clay differed in the two wells. 

The upper clay bed of the Tampa formation is best exposed at 
the pit of the Tampa Brick Co., on the bank of Hillsboro River 5 
miles northeast of the city, where an exposure of 10 to 14 feet of light- 
green siliceous clay is unconformably overlain by 2 to 4 feet of light- 
gray Pleistocene sand. The clay is very plastic and is said to make 
excellent brick. Scattered throughout the deposit are numerous 
cobbles and bowlders of chert which represent silicified corals. The 
major portion of the exposure is of a light-greenish color, but toward 
the bottom the clay becomes gray and is interbedded with thin nodu- 
lar layers of limestone. 

A light-green siliceous clay similar to that described above was seen 
on the west side of Old Tampa Bay, near Safety Harbor (Espiritu 
Santo Springs), where the section shows 4 to 6 feet of white Pleisto- 
cene sand resting unconformably on 6 feet of greenish clay. On the 
beach near this exposure are several large chert bowlders, which were 
probably derived from beds beneath the clay. About a mile north 
of the post office the following section was observed : 

Section 1 mile north of Safety Harbor post office. 

Feet. 

Sand, white (Pleistocene) 2-4 

Sand, dark brown, partly indurated 1-6 

Clay, light greenish, thinly laminated 5 



GEOLOGY OF NOBTHEEN AND CENTKAL FLOKIDA. 107 

Numerous exposures of cherty limestone on the Gulf coast, near 
Clearwater, are probably to be correlated with the rocks at Tampa, 
but in the absence of paleontologic evidence this correlation must 
be regarded as merely tentative. A generalized section at this locality 
was obtained from well records and observations along the beach. 

Generalized section near Clearwater. 

- Feet. 

Sand, white (Pleistocene) 12 

Clay, light colored 14 

Limestone, light colored; with chert concretions ^1 

Clay, bluish, laminated, marly; with chert concretions 2-4 

Limestone, light gray; with chert concretions 2-3 

A generalized section near Lapenotieres Spring is given by Dall : ^ 

Generalized section near Lapenotieres Spring. 

Hunius, yellow sand, etc 6-36 inches. 

Tampa limestone 10-15 feet. 

Orthaulax bed 7 inches to 10 feet. 

The limestone of the Tampa formation is exposed near the pumping 
station, where it has been quarried to a depth of over 15 feet, and at 
intervals along Hillsboro River for more than 15 miles inland. 
Probably the best exposures are in the excavations near the 
Sulphur Spring, northeast of Tampa, and at the rapids about a 
mile above the spring. The same limestone was observed resting on 
the ''silex bed" at the railroad crossing over Sixmile Creek, where the 
limestone is immediately overlain by fossiliferous Pleistocene shell 
marl which grades upward into coarse white sand. 

Section one-eighth mile below railroad bridge at Orient ( Tampa) . 

Feet. 

Marl, soft, white 6 

Quartz sand, light gray to buff, fine grained 3 

Shell marl, gray (Pleistocene) 1-2 

Limestone, white, soft, with some gastropods and other fossils 5 

The shell marl is thin but persistent; it rests unconformably upon 

the limestone. 

Section at railroad bridge at Orient {Tampa). 

Feet. 

Sand, fossiliferous, white 2 

Marl, white 6 

Sand, light gray 1 

Shell marl, gray 0-1 

Limestone, gray to yellow; very fossiliferous in places 6 

The shell marl rests unconformably upon the limestone and is evi- 
dently the bed shown in the preceding section. The limestone in 
both of these sections is what has commonly been called ''Tampa 
limestone." In the section at the railroad bridge some ''silex" near 
the base evidently represents the ''silex bed" at Ballast Point. 

1 BuU. U. S. Geol. Survey No. 84, 1892, p. 118. 



108 GEOLOGY AND GEOUND WATERS OF FLOEIDA. 

ALUM BLUFF FORMATION. 

Members. — The name Alum Bluff formation as here used includes 
beds that belong stratigraphically above either the Chattahoochee 
or the Hawthorn formations and below the marls and limestones 
of Miocene age. This usage differs from that of Dall/ who appears 
to have regarded the Chipola marl as distinct from the Alum 
Bluff formation. The Alum Bluff formation includes two different 
though closely related members, the Chipola marl and the Oak Grove 
sand. To these is added a third member, recently discovered by 
Vaughan ^ in West Florida and called the Shoal River marl member, 
from the stream along which it is best exposed. The Chipola marl 
member and the sands of the type locality at Alum Bluff were first 
described by Langdon, who referred them to the Miocene.^ 

The type locality of the Chipola * marl member is at McClelland' s 
farm near Baileys Ferry on Chipola River, and the Alum Bluff for- 
mation is named from the bluff on Apalachicola River where it was 
first examined. The fuller's earth deposits which represent the 
Alum Bluff formation east of Apalachicola River have been men- 
tioned by a number of writers, but the first comprehensive descrip- 
tion of them was given by Vaughan ^ in 1901. The Oak Grove sand 
member was described by Dall ^ in 1893. 

Exposures of limestone on Sopchoppy and Ochlockonee rivers, 
some 5 or 6 miles from the town of Sopchoppy, have been called 
^^ Sopchoppy limestone." This rock was first described by Dall,' 
who assigned it to about the horizon of the Chipola marl member. 
In this report it is tentatively included with the Alum Bluff forma- 
tion, but further investigation is needed to determine its exact strati- 
graphic relations. 

The limestones and marls on Manatee River near EUenton were 
thought by Heilprin ^ to belong to the Miocene, but are probably 
somewhat older. They are here referred tentatively to the Oak 
Grove sand member of the Alum Bluff formation, but this correlation 
is subject to revision if subsequent investigations should show that 
the fauna is characteristic of some other horizon. 

StratigrapJhic position. — The Alum Bluff formation is conformable 
upon both the Chattahoochee and the Hawthorn formations. No 
distinct evidence of a stratigraphic break between these formations 

■ 1 Dall, W. H., Cenozoic geology along the Apalachicola River: Bull. Geol. Soc. America, vol. 5, 1894, 
p. 167. 

2 Vaughan, T. W., unpublished notes. 

3 Langdon, D. W.j jr.. Some Florida Miocene: Am. Jour. Sci., 2d ser., vol. 38, 1889, p. 32. 
* Bui. U. S. Geol. Survey No. 84, 1892, p. 122. 

6 Vaughan, T. W., Fuller's earth: Mineral Resources U. S. for 1901, U. S. Geol. Survey, 1902, pp. 921-948. 
6 Bull. Geol. Soc. America, vol. 5, 1893, pp. 16&-167. 
1 Bull. U. S. Geol. Survey No. 84, 1892, pp. 119-120. 

8 Heilprin, Angelo, Explorations on the west coast of Florida: Trans. Wagner Free Inst. Sci., vol. 1, 1887, 
p. 13. 



GEOLOGY OF NOKTHERN AND CENTRAL FLORIDA. 109 

has been noted, and their faunas are closely related. At Alum Bluff 
on Apalachicola River and at Jacksons Bluff on Ochlockonee River 
marls of Miocene age rest upon an eroded surface of the Alum Bluff 
formation, but farther west, in Walton County, it is possible that they 
may be conformable. 

Lithologic character. — The Alum Bluff formation consists of marl, 
sand, and clay, which are in places fairly distinct but are more 
commonly interbedded. Limestones also occur in the formation, 
but they are not extensively developed and commonly contain 
enough earthy material to form marls. Shell marls with a calcareous 
or sandy matrix are common, occurring in many places interbedded 
with nearly pure sand. In general the beds belonging to this forma- 
tion are light gray, but sporadically shades of green or yellow prevail. 

At Alum Bluff on Apalachicola River, Dall ^ gives the following 
section : 

Section at Alum Bluff on Apalachicola River. 

Feet. 

1. Superficial sands : 8J 

2. Red clay 2^ 

3. Reddish and yellowish streaked sands 66 

4. Aluminous clay 24 

5. Chesapeake gray marl 35 

6. Alum Bluff sands with streaks of clay 21^ 

7. Hard Chipola marl to water (variable) 3^ 

Total thickness above water 160| 

The composition in detail of these several beds is as follows: 

No. 1. — Pale yellowish-gray incoherent sand. 

No. 2. — Hard reddish clay, weathering with vertical face. 

No. 3. — Streaky yellowish and reddish sands, with small little-worn gravel of 
siliceous character mixed with it. Near the lower third a few obscure impressions, 
possibly representing fossils, were observed by Mr. Stanley-Brown . The lower 3 feet of 
the sands is more or less loamy from admixture with underlying clay. They are dis- 
tinctly stratified in conformity with the other beds of the bluff. 

No. 4- — Tough gray aluminous clay weathering nearly vertical, with a few fragments 
of vegetable matter in it and some obscure indications of gastropod and bivalve fos- 
sils, the shells entirely dissolved and represented chiefly by color marks in the clay. 
The appellation of "lignitic," heretofore applied to this clay on the authority of Mr. 
Johnson, can not be regarded as justified, as the amount of phytogene material is 
trifling. The fossils may have been marine or fresh water. No satisfactory evidence 
is afforded by their faint traces, as observed by us. 

No. 5. — Bluish-gray tough clayey marl, replete with characteristic Chesapeake 
fossils, especially Mactra congesta. The upper 6 inches is discolored by iron oxide, 
derived from the water oozing from the bed above, which has also dissolved the shells, 
leaving only cavities. Toward the north, at a point near the camp, the Chesapeake 
is thinned to 5 or 6 feet in thickness. 

Nos. 6 and 7. — The Chipola marl is compact and of a dark-reddish color from 
hydrated peroxide of iion contained in it. The fossils, which are abundant, are rather 
soft. Orthaulax is the most common shell; there are no traces of Orbitolites. The 

1 Dall, W. H., Bull. Geol. Soc. America, vol. 5, 1894, p. 157. 



110 GEOLOGY AND GROUl^D WATERS OF FLORIDA. 

matrix is chiefly sand mixed with clay. At least 6 or 8 feet of the Chipola is below the 
water; it rises at the lowest stage of the river from 3 to 11 feet above the water's edge, 
weathering almost like a rock. There is no well-defined line of separation between 
the marl and the Alum Bluff sands (No. 6) above it, but the change takes place in a 
space of 5 feet, the lower portion of the sands containing more or less of the Chipola 
faxma. Above this they are mottled bright ferruginous and yellow and exhibit dis- 
tinct marks of cross bedding. They contain sheets — laminae or lenticular streaks of 
clay — which show abundant leaf remains resembling willows and other water-loving 
plants, while the sands in the lower part of the bed contain large leaves and stalks of 
palmetto or other palm-like vegetation, the thicker parts of which are reduced to the 
condition of lignite. These are too friable to remove without previous hardening 
applied in situ. The upper part of these sands did not show any fossil remains at the 
points where we examined them. 

Toward the north, where the bluff is much lower and the ''Chesa- 
peake" thuis out to 5 or 6 feet in thickness, the sands below it are 
unfossiliferous and modified. The upper part is more exclusively 
sandy, and lower down the bed has the clayey character and greenish 
color of the oyster marl at Rock Bluff, a few miles above; at the 
latter place, however, the green marl contained no fossils. 

The typical Alum Bluff formation is composed of coarse, light 
greenish-gray to white argillaceous sands, which in many places 
show cross bedding and generally contain more or less interbedded 
clay and fuller's earth. One of the most characteristic features 
of the sands is the presence of innumerable flakes of white mica — 
the ''isinglass" of the well diggers. The change from the shell marls 
of the Chipola marl member is by a transition zone which contains 
some of the same species of shells which characterize the marls. This 
zone also contains nodules of calcium carbonate, many of which 
inclose fossils. The upper part of the sands is usually free from 
shells but here and there contains impressions of leaves and frag- 
ments of plants. Locally, the Alum Bluff formation contains some 
clay, and near Chattahoochee it consists of greenish sticky marl. 

The fuller's earth has the appearance of a dense, hard, fine-grained, 
siliceous clay. It is thinly laminated, and is generally light gray to 
greenish in color. Sand partings occur in places, but they are 
comparatively scarce, the material usually being homogeneous. Beds 
of sand and clay are commonly associated with the fuller's earth, 
and the sections generally consist of interbedded sand and clay. 

Thickness. — The aggregate thickness of the Alum Bluff formation 
is at least 135 feet, but the maximum thickness observed at any 
locality is scarcely one-half that amount. The thickness of the sands 
of the Alum Bluff formation at the type locality is about 20 to 25 
feet, but farther north, at Rock Bluff, Dall ^ reports a maximum of 63 
feet. The fuller's earth generally occurs in beds 2 to 10 feet in thick- 
ness associated with several feet of clay and sand or sandstone. In 

1 Dall, W. H., and Stanley-Brown, Josepli, Cenozoic geology along the Apalachicola River: Bull. Geol. 
Soc. America, vol. 5, 1894, p. 166. 



GEOLOGY OF NORTHERN AND CENTRAL FLORIDA. Ill 

some sections twQ or more beds of fuller's earth occur, separated by 
beds of sand and clay. The maximum observed thickness of fuller's 
earth in a single section is about 15 feet, and the aggregate thickness 
of the associated clays and sand which appear to belong to the same 
beds is not less than 20 feet. 

Physiographic expression. — The members of the Alum Bluff for- 
mation, with the exception of the Chipola marl member, are soft and 
easily eroded into deep valleys but are sufficiently resistant to form 
steep slopes. Thus the region where the Alum Bluff formation lies 
near the surface is characterized by a topography that has been 
formed by surface erosion and that is in marked contrast to the sink- 
hole topography of the central part of the peninsula. However, 
wherever the formation is thin, solution has given rise to many sink 
holes and the topography is a composite of valleys and poorly drained 
depressions. 

Paleontologic character, — ^As already noted, the typical sands and 
clays of the Alum Bluff formation are sparingly fossiliferous, the 
lower part containing a fauna allied to the Chipola marl member and 
the upper part being characterized by plant remains. The fuller's- 
earth beds contain a very poorly preserved fauna, from which 
Vaughan ^ secured enough material to show that they belonged to 
the Alum Bluff formation. He also notes the fact that these beds 
contain Carolia floridana Dall, which is characteristic of the ApalacKi- 
cola group. Both the Oak Grove sand member and the Shoal River 
marl member are very fossiliferous. 

Structure. — The Alum Bluff formation shows no marked peculiar- 
ities of structure. Though it has undoubtedly been affected by 
some of the movements which resulted in the general arching of the 
strata of the State, the disturbance has not produced any effect, 
except to give a general seaward dip to the beds. If any local 
deformation has produced folding of the beds belonging to the 
Alum Bluff formation, the existence of the folds has not yet been 
detected. However, this may be due to the imperfect exposures. 

Areal distribution. — Micaceous white sands belonging to this 
formation are well exposed on Tenmile Creek at Carrs Mill, Calhoun 
County, and at intervals for about a mile farther upstream, where 
they consist of coarse light-gray sands containing many flakes of 
silvery-white mica. Upon weathering, the sand changes to a 
pale-yellow color from the presence of hydrated iron oxide. The 
sands show some evidence of cross bedding and appear to be desti- 
tute of organic remains. Similar sands are reported in wells farther 
west in Walton County, and exposures were noted beneath the 
Shoal River marl member near Knoxhill, Walton County. 

Vaughan, T. W., Fuller's earth: Mineral Resources U. S. for 1901, U. S, Geol, Survey, 1902, pp. 926-932. 
76354°— wsp 319—13 8 



112 GEOLOGY AND GROUND WATERS OF FLORIDA. 

Vaughan's investigations ^ have shown that the fuller 's-earth beds 
are the stratigraphic equivalent of the sands at Alum Bluff. About 
4 miles southeast of River Junction at an abandoned fuller's earth 
mine belonging to Mr. Hymeson, Vaughan reports the following 
section : 

Section 4 miles southeast of River Junction. 

Feet. 

4. Surface sands, beneath which are reddish sands containing some 

quartz gravel 60 

3. Clay, stiff, blue; the top of the fuller's earth deposit 4 

2. Fuller's earth. A considerable amount of the overburden had 
been thrown off, but due to weathering and wash there is really 
no good exposure. Judging from what can now be seen, accord- 
ing to a roughly leveled section, it seems that the deposit is at 
least 8 feet thick, and it may be thicker. There is no means of 
determining its horizontal extent. A box of the earth was 
collected from the best exposure 8+ 

1. Immediately beneath the fuller's earth there appears to be a 
deposit of sandy, very stiff blue clay. Thickness unknown. 

The following is , the generalized section, according to aneroid 
readings made in the vicinity of River Junction: 

Generalized section near River Junction. 

Feet. 

Surface sands 60 

Clay and fuller's earth 10 

Not exposed ; probably argillaceous sands 17 

Chalk or limestone; some layers of marl (Chattahoochee) 88 

The rocks beneath the Chattahoochee formation are not exposed 
near River Junction. 

The inference from this section apparently would be that the 
Chattahoochee formation is 88+ feet in thickness and is separated 
by 17 feet of unexposed strata from the deposit of fuller's earth above. 
This would stratigraphically correlate the fuller's earth with the 
Alum Bluff formation. 

The following detailed description and section of Rock Bluff on 
Apalachicola River was published by Dall and Stanley-Brown.^ 
The writer is of the opinion that the fuller's earth stratum corresponds 
to No. 3 of their section: 

The lower part of the bluff formed by the Chattahoochee is vertical, rising 12 feet 
above the water, and presumably nearly as much below it at low stages of the river. 
Above this is a mass of marl varying from bluish green to gray in color, weathering 
white, more arenaceous below and more marly above, replete with oyster shells, a 
fine, large Anomia, a Pecten, like young madisonius (but, as observed by Foerste, only 
four-sevenths the size of that species; it is really a Chipola species), a Turritella, and 
many Balani. This assemblage of species indicates a shallow-water oyster-reef fauna 
unquestionably belonging to the "old Miocene" (Apalachicola group) and forming 

1 Fuller's earth: Mineral Resources U. S. for 1901, U. S. Geol. Survey, 1902, pp. 926-927. 

2 Bull. Geol. Soc. America, vol. 5, 1894, pp. 155-156 . 



GEOLOGY OF NOKTHEEN- AND CENTRAL FLORIDA. 113 

the shoal-water equivalent of the Chipola and Alum Bluff beds, especially the latter. 
Above this marl lie the red Lafayette clays and gravels — in this case worked-over 
materials — variable in thickness, owing to denudation, but apparently averaging 
about 15 feet, and covered with a thin layer of superficial soil and sand. This section 
was carefully measured with a steel tapeline, due allowance being made for the inclina- 
tion of the tape from the vertical. It shows the finest and thickest section of the 
greenish marl exposed anywhere on the river. The contact of the marl with the 
Chattahoochee limestone is distinct and without apparent unconformity or transition 
beds of any kind. 

This section was measured on the highest part of the bluff, which is the first 
approached as the turn of the river is made in descending: 

Section at Rock Bluff, Apalachicola River. 

Feet. 

1. Superficial sands, thin and variable, say 3 

2. Reddish clayey sand and gravel, about 15 

3. Greenish-white compact marl, with fossils ". 67 

4. Chattahoochee limestone, to water 12 

Total thickness above water 97 

The list of fossils given under the head of paleontologic characters 
indicates the correctness of the conclusions reached on the bases of 
purely stratigraphic work, for they show that the fuller's earth beds 
are to be correlated with the Alum Bluff formation. 

In 1900 the fuller's earth deposits of northern Florida were in- 
vestigated by Vaughan/ and the results of his studies were published 
in Mineral Resources of the United States for 1901. He says: 

There is an exposure of fuller's earth on the south bank of Mosquito Creek, near 
the foot of a bluff, on land belonging to Mr. John D. McPhaul. The overburden 
is here too great for working. The deposit is along a small stream running north 
into Mosquito Creek in the NW. i sec. 16, T. 3 N., R. 4 W. A sample was taken 
at this locality where a pit had been sunk. 

A section in the pit shows overburden (sand), 4 feet; fuller's earth, 6 feet. The 
bed was not completely penetrated. 

The material was also exposed in the bed of a creek near by. The slope 'down 
to the creek valley is gradual. A strip several hundred yards wide and probably 
half a mile long could be worked. Fuller's earth occurs also on the land of Mr. 
A. J. Key, in sec. 15, T. 3 N., R. 4 W.; and on the land of Mr. Elias Howell, in sec. 
10, T. 3 N., R. 4 W., and extends also along the creek about one-half mile below 
Mr. McPhaul's. 

The following is a section through the fuller's earth at the Chesebrough Manu- 
facturing Co's. mine, 1 mile south of Quincy. The section was given by T. L. 
Ward. 

Section of Chesebrough Manufacturing Co's. mine. 

Feet. 

5. Overburden of clay and sands 7 

4. Fuller's earth (average) 4 

3. White argillaceous sandstone containing fossils 5 

2. Fuller's earth 9 

1. Soft sandstone, sand, and fuller's earth 15 



Vaughan, T. W., FuUer's earth: Mineral Resources U. S. for 1901, U. S. Geol. Survey, 1902, pp. 92&-932. 



114 GEOLOGY AND GEOUND WATEES OF FLOEIDA. 

It is estimated that there are about 10,000 tons to the acre. The mine was visited 
in company with Mr. Ward. About 2 acres have been mined, and 20,000 tons were 
taken out. Mr. Ward states that operations were begun in 1895 and closed down 
in December, 1899, because the Standard Oil Co. had sufficient earth on hand for 
the present. Bed No. 3 contains numerous poor fossils. Several species were col- 
lected, of which the following is a list: 

Cypraea, agreeing in form and size with C. pinguis Conrad from the Chipola horizon; 
Murex mississippiensis Cojiisid'f var.; Fulgur spiniger Conrad?; Modulus sp.; Crucihu- 
lum auricula Gmelin; Area staminata Dall; Pecten (Nodipecten'?) sp.; Cardita serricosta 
Heilprin, and Chione sp. 

These fossils indicate an upper Oligocene horizon, corresponding stratigraphically 
with No. 3 of Dall and Stanley-Brown's Rock Bluff section, which was given on a 
preceding page. 

A specimen of Carolia fioridana Dall, from the fuller's earth horizon at Quincy, 
is in the United States National Museum. This is considered an index fossil of our 
upper Oligocene. 

An examination of the section at the Owl Commercial Co's. mine disclosed the 
following exposure: 

Section of the Owl Commercial Co^s. mine. 

Feet. 

Overburden 5-20 

Fuller's earth 6-10 

Sandstone containing crystals and lumps of calcite or aragonite 3-4 

Fuller's earth 5- 6 

The mining is done by stripping. 

Fuller's earth occurs along Quincy Creek above the Owl Commercial Co's. works, 
about IJ miles west of Quincy, on land belonging to Mr. William Bruce, in sec. 12, 
T. 2 N., R. 4 W. A specimen taken from an auger bore was donated by Mr. Bruce. 
The overburden along the creek flat is 4 or 5 feet thick. Mr. Bruce also donated 
some pieces of the material which came from a pit that is at present filled with water. 
A pit has also been dug in sec. 2, T. 2 N., R. 4 W., on land belonging to Messrs. Taussig 
and Wedeles. Some pieces were picked up out of the dump around this hole. The 
overburden is from 4 to 5 feet thick, the same as on Mr, Bruce 's land. 

The fuller's earth in these localities has not been thoroughly explored. It seems 
to be of good quality, the overburden is not great, and the land is flat. Transpor- 
tation by railroad is within one-half to three-fourths of a mile. From what Mr. Bruce 
says, the deposit is thick enough for profitable working — about 8 feet. 

[In Leon County] 12 miles west of Tallahassee, on property belonging to Messrs. 
W. H. Allen & Sons, are occurrences of fuller's earth. Several pits have been sunk 
by Mr. Rosendale. The overburden is about 6 feet, and there are about 8 feet of 
fuller's earth. The writer was not able to get fresh specimens, hence pieces from 
the dump were selected. The land lies rather flat, along a small creek running into 
Ochlockonee River. 

A section on the Seaboard Air Line Railway, about 1 mile east of Tallahassee, 
at milepost 163, shows the following exposures: 

Section on Seaboard Air Line Railway. 

The upper 25 or 30 feet at the ends of the cut are reddish, yellowish 
sands. Feet. 

Sands with clay partings 5-10 

Whitish or bluish clay resembling fuller's earth in thin laminae 
with sand partings 4- 5 



GEOLOGY OF KOBTHERN AND CENTRAL FLORIDA. 115 

In a curve in the railroad track between mileposts 163 and 164 is another 
cut between 15 and 20 feet deep, and the same section as above described was again 
seen. The clay at the base resembles more closely fuller's earth than in the first- 
described section. It contains less sand. 

A fuller's earth horizon is also mentioned in the Jacksons Bluff 
section, which is included under the discussion of the Miocene. 

On the bank of Ochlockonee River, a mile north of Holland post 
office, there is an exposure of hard light-gray limestone, which was 
formerly quarried. The surface is now almost obscured by debris, 
but it is still possible to find small exposures which indicate that the 
beds are at least 12 feet thick. The upper 4 feet contain many 
specimens of Carolia jloridana Dall, but the remainder of the outcrop 
is conglomeratic and appears to be almost destitute of fossils. 

A record of a well sunk by J. A. Henderson near the western limits 
of Tallahassee was furnished by Vaughan. It shows 25 feet of 
sands and clays, underlain by 75 feet of Hmestone containing clay 
layers. 

The limestone furnished Ostrea rugifera Dall, Pecten chipolanus 
Dall, Anomia sp. 

On Rouses Mill Creek, near West Sopchoppy, about 10 feet of soft 
light-gray sandstone is exposed. The rock is friable and resembles 
the Alum Bluff formation in texture. A few fossils occur in the 
sandstone, but they are too friable to obtain good specimens, only one 
identifiable specimen of Pecten madisonius var. sayanus Dall having 
been obtained. 

At West Sopchoppy there is a bed of very fossiliferous marl which 
probably lies stratigraphically above the soft sandstone at the mill. 
The marl contains some material like that at the mill, but is much 
more calcareous and contains many shells. The thickness of the 
outcrop is about 10 feet, but the base of the marl is not exposed, and 
hence its maximum thickness may be considerably greater. The 
marl furnished specimens of Carolia jloridana Dall and Scutella sp. 

In addition to the locahties given above, the Alum Bluff formation 
is exposed at numerous locahties. 

An exposure at White Springs, on Suwannee River, is referred to the 
Alum Bluff formation. The section given below was measured with 
a hand level at the point where the wagon bridge spans the river. 

Section at White Springs, on Suwannee River. 

Feet. 

1. Loam, dark colored, sandy 1 

2. Sand, dark colored, semi-indurated 5 

3. Unconformity. 

4. Clay, greenish, thinly laminated, siliceous 8 

5. Sand, light yellow, containing many casts of shells 17 

6. Sand, fine grained, light gray 11 

7. Marl, light gray, arenaceous and calcareous, sandy 51 



116 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

Feet. 

8. Marl, light gray, arenaceous, with nodules of chert 12 

9. Sand, bluish, and light-green sticky marl containing thin layers 

of limestone in alternating beds, nodules of chert, and some 
imperfect oyster shells 2 

10. Sand, gray, with thin nodular and brecciated layers of limestone . 3 

11. Sand and light-gray shell marl in alternating beds; many well- 

preserved fossils near base of section 6 

River level reported 4 feet above low-water stage. 

Nos. 1 and 2 of the foregoing section are the ordinary surface 
sand which covers a large part of the State. 

Nos. 4 to 11, inclusive, probably belong to the Alum Bluff 
formation. 

From the material collected near the base of No. 11 Vaughan 
identified Ostrea rugifera Dall, Pododesma scopelus Dall, and Pecten 
madisonius var. say anus Dall. 

On Ochlockonee River, about one-fourth mile above Stuarts Bridge, 
thinly laminated, Ught-gray to white marl outcrops with a thickness 
of about 6 feet. The material is so brittle that it was difficult to 
secure fossils. 

Rocky Bluff, on Manatee River, about a mile from EUenton, was 
visited by Heilprin,^ who says : 

The "Bluff" we found to be a ledge of rock, rising 2 or 3 feet above water level at 
the time of our visit, and consisting of at least two well-defined layers — a basal white 
"marl " and yellowish sandstone and an overlying siliceous conglomerate. The latter 
is almost entirely deficient in organic remains, whereas the marl is densely charged 
with them. Among the recognizable forms occurring here I determined a number of 
well-known and distinctive Miocene species of moUusks, such as Pecten jeffersonius, 
P. madisonius, Perna maxillata, Venus alveata, Area incongrua, etc., which left no 
doubt as to the age of the deposits in which they were embedded. 

The exposures in the vicinity of Ellen ton are of considerable 
interest because they contain valuable deposits of fuller's earth. 
Three-fourths mile southeast of Ellenton a section was measured which 
showed the following beds: 

Section three-fourths mile southeast of Ellenton. 

Feet. 

Loam, dark gray to black, sandy 4- 6 

Sand, dark colored, clayey, containing chert pebbles, worn and 
rounded fragments of bones, and shark teeth. "Clam" shells are 

said to occur in this bed, but none could be found 0- 2 

Unconformity. 

Fuller's earth, dense, thinly laminated, light gray, weathering pale 
yellow 5- 8 

9-16 
About one-fourth mile farther east another exposure shows thinner 
beds of fuller's earth and underlying limestone. 

1 HeUprin, Angelo, Trans. Wagner Free Inst. Sci., vol. 1, 1887, p. 13. 



GEOLOGY OF KOBTHEBN AND CENTRAL FLORIDA. 11 Y 

Section at Rocky Bluff, about a mile southeast of Ellenton. 

Feet. 

Loam, light and dark gray, sandy, about 1 

Loam, black, clayey, with bone fragments 1 

Unconformity. 

Fuller's earth, light gray 2-3 

29 



Limestone, dense, light gray to pale yellow, impure, fossiliferous 



14+ 

The material which Heilprin ^ called sandstone appears to be a 
coarse-grained sandy limestone. Shells and fragments of bone are 
numerous in certain stratums, but the rock is so brittle that it is 
difficult to get good collections. The presence of Turritella alcida 
Dall and Pecten madisonius var. sayanus Dall have led to this Ume- 
stone being referred to the Alum Bluff formation, but larger collec- 
tions may show that it belongs to some other subdivision of the 
Apalachicola group. The exact relation of the fuller's earth bed to 
the limestone was difficult to determine, though it is apparently 
conformable; and if so, it belongs to the Oligocene. Heilprin's 
reference of the exposures at Rocky Bluff to the Miocene appears to 
have been an error, unless he intended to use the term Miocene, in 
the sense in which it was formerly employed, to include the 
Apalachicola group of the Oligocene. 

Chipola marl member. — The Chipola marl member forms the basal 
portion of the Alum Bluff formation and rests conformably on the 
Chattahoochee and the Hawthorn formations. At the type locahty 
of the Alum Bluff formation it constitutes the basal division of that 
formation, but farther north it thins out, permitting the sandy beds 
of the Alum Bluff to lap over on the Chattahoochee formation. This 
overlap is probably explained by the gradual shoaling of the water, 
which prevented the development of abundant organic life toward 
the north. As the sands were deposited farther south they gradually 
encroached upon the area where marl had previously been forming. 
According to this hypothesis, there would be no necessity for an 
erosion interval between the Chattahoochee and the Alum Bluff 
formations, as a gradual emergence of the land or a filling of the shal- 
low water along the margin of the sea would permit the deposition of 
sands upon the limestones and marls. 

When fresh the Chipola marl member consists of a light-gray to 
yellow marl, containing many shells and shell fragments. The 
matrix is composed of calcareous clay containing a small proportion 
of fine sand. When weathered the marl becomes dark-yellow or 
reddish-yellow from the presence of hydrated iron oxide. The 
character of the deposit indicates comparatively quiet water with 

1 Above water. 2 Below water. 3 op. cit. 



118 GEOLOGY AKD GEOUND WATERS OF FLOElDA. 

conditions especially favorable for the development of organic life. 
In some localities, as at White Springs on the Suwannee, the Chipola 
is represented by a very sandy marl. The ^^Sopchoppy limestone," 
which Dall has assigned to the Chipola marl, varies from a soft white 
or light-gray to a dense gray limestone, some of which is cherty. 
Some beds of soft sandstone are doubtfully referred to this stratum. 
The beds contain layers which appear to have been broken and 
recemented, thus forming a brecciated limestone which is said to be 
somewhat phosphatic. Locally the rock is abundantly fossiliferous, 
containing imprints of shells and fragments of bones. 

The Chipola marl member of the Alum Bluff formation is not known 
to have a thickness of more than 15 feet and the average is probably 
only a few feet. The limestone belonging to this member is so imper- 
fectly known that it is difficult to make a satisfactory estimate of 
its thickness. The maximum reported exposure is about 10 feet. 

The fossils of this member have been studied by Dall,^ who says: 

The fauna comprises 333 species, to which we may expect additions on further 
exploration. A species of Orthaulax different from that found in St. Domingo or the 
Tampa Orthaulax bed, a rich development of the genus Marginella, a species of the 
group of Oliva called by von Martens Omogymna, a species of Spheniopsis, heretofore 
only known from the European Oligocigne; these are among the interesting features 
of the fauna. 

The group of species is distinctly subtropical but less indicative of warm seas than 
the Bowden marl of Jamaica, with which the Chipola beds have 16 species in common. 
Only one species is known to be found both in the Chipola beds and the Oligocene of St. 
Domingo. About half the species in the Chipola marl are peculiar to it, and of the 
others the largest percentage is found in the Tampa silex beds, while in the subse- 
quent Oak Grove sands 24 per cent of the Chipola species occur. Thirty-five species 
survive to the existing fauna. 

According to Dall ^ the '^Sopchoppy limestone'' contains orbito- 
lites and ''about 30 species of shells, most of which are common to 
the Chipola marl or the Orthaulax beds. " Judging from the presence 
of fragments of bones occurring in this limestone at some localities, 
a vertebrate fauna of considerable size is doubtless represented, but 
no attempt has been made to secure collections and hence its charac- 
teristics are unknown. 

The type locality of the Chipola marl member is the McClelland 
farm, which is situated on the west side of Chipola Hiver just south 
of Tenmile Creek. Here the marl was formerly mined, but at the 
present time the pit is covered with sand and debris, so that the 
deposit can only be reached by digging. The section given by 
Dall ^ is as follows : 

1 DaU, W. H., Trans. Wagner Free Inst. Sci., vol. 3, pt. 6, 1903, pp. 1574-1575. 

2 Bull. U. S. Geol. Survey No. 84, 1892, p. 120. 

8 Dall, W. H., Bull. Geol. Soc. America, vol. 5, 1894, p. 159. 



GEOLOGY OF KOBTHEBH AHD CENTRAL FLORIDA. 119 

Section on the McClelland farm, on Chipola River. 

Feet. 

Superficial sands, 1 to 3 feet, say 2 

Chipola marl, varying from 7-12 

Chattahoochee limestone at water's edge, extending below not less 

than 6 



20 

The marl is exposed on tlie north bank of Tenmile Creek, where it 
attains a thickness of 6 to 12 feet, and is underlain by the Chatta- 
hoochee formation, which is exposed at a natural bridge 200 or 300 
yards farther downstream. At this locality the marl has the same 
general characteristics as in McClelland's marl pit. Other small 
exposures are reported on Chipola Kiver, near the McClelland farm, 
and at the base of Alum Bluff. 

Oak Grove sand member. — On paleontologic grounds Dall ^ has 
correlated the Oak Grove sand member with the typical sands of 
the Alum Bluff formation. The correlation ^ has been made because 
of the presence in both of Ostrea trigonalis, Pecten sayanus, a Podo- 
desmus, and Turritella alcida Dall. 

The Oak Grove member consists of fine-grained, light-gray to 
greenish sands containing many excellently preserved shells. It is 
a sandy shell marl, which in many places has a considerable admix- 
ture of calcareous material. Some soft marly limestones on Manatee 
Kiver are tentatively referred to this member. The Oak Grove 
member is not fully exposed at the type locality and may attain a 
thickness of several feet, but its observed thickness is only a few 
feet. 

The fauna of the Oak Grove member is closely related to that of 
the Chipola marl member, but it contains large species of both Car- 
dium and Lyropecten, which appear to foreshadow the large species 
of those genera occurring in the Miocene marls. 

Owing to the heavy rains, the Oak Grove sand member was sub- 
merged at the time that locality was visited. The exposure is said 
to be less than 4 feet in thickness and to consist of light-gray ex- 
tremely fossiliferous sand. The type locality was subsequently 
examined by Vaughan, who reports the following section: 

Section of bluff, Yellow River, about 100 yards below road bridge. 

Feet. 
Sands, fine, yellow 9 

Marl, very fossiliferous, gray, sandy, extending at least 1 foot below 
level of water in the river 2 

11 

1 Bull. Geol. Soc. America, vol. 5, 1894, pp. 166-167, 170. 

2 Trans. Wagner Free Inst. Sci., vol. 3, pt. 6, 1903, p. 1588. 



120 GEOLOGY AND GBOUND •V\^ATEBS OF FLORIDA. 

The fossiliferous marl forms a platform 20 to 30 feet wide along the base of the bluff, 
sloping (at the present stage of the water) from 2 feet next the bluff to 1 foot along the 
river edge above the water. The surface in places is practically covered with shells 
freed from the matrix. The weathered marl is an aehy gray but when fresh is dark 
bluish. 

Vaughan also examined the exposure at Senterfitt Creek, which he 
describes as follows: 

After studying this exposure [Oak Grove, Yellow River], and collecting from it, I 
drove to the Senterfitt gristmill and revisited the exposure from which I collected 
in May, 1903. The latter locality is by aneroid 30 feet above the fossil bed at the 
Oak Grove Bridge and is 2 miles northeast of that locality. The marl bed on Sen-r 
terfitt Creek is therefore stratigraphically slightly above the Oak Grove horizon. 

The Senterfitt horizon seems very persistent, extending at least from the Yellow 
River to Argyle. 

Vaughan also examined an exposure of marl on the south side 
of the river at Crowders Crossing in sec. 5, T. 3 N., E. 21 W. At this 
locality a blue or bluish-green marl rises about 2 feet above the 
river at a very low stage of water. This exposure is probably the 
stratigraphic equivalent of the Oak Grove sand member. 

Slioal River marl member. — The Shoal River marl member lies 
stratigraphically about 30 feet above the Oak Grove sand member. 
It thus forms the upper part of the Alum Bluff formation. In the 
following section at Shell Bluff, the lower sand represents the Oak 
Grove sand member and the upper fossiliferous marl the Shoal 
River marl member. 

Section at Shell Bluff. 

Feet. 
Gravel, mostly quartz, in rather coarse red sands, on slope; gravel 

ellipsoidal, one-half inch probably usual length, rarely 1 inch. . 30 

Sand, gray, finer, blotched yellow, decidedly argillaceous lOi 

Shell marl, greenish; matrix arenaceous, fine, fossiliferous (Shoal 

River marl member) 2J 

Sand, nonfossiliferous, coarser, greenish; becoming argillaceous 

at base 3 

Clay, green | 

Sands, coarser, gray, greenish; last 2^ feet loose, purple and white. 6 

Unexposed 15 

Sands, nonfossiliferous, green, oxidized yellowish on surface (Oak 

Grove sand member) 10 



80± 

Lithologically the Shoal River marl member consists of inter- 
bedded sands, clays, and marls. In most places the color is greenish, 
oxidizing yellow; in a few it is whitish or purplish. The material 
varies from fine clay to sand. 

The Shoal River marl member of the Alum Bluff formation is 
about 50 feet thick. It is very fossiliferous; extensive collections 
from it have been made by Vaughan but have not yet been studied 



GEOLOGY OP NORTHEKN AND CENTRAL FLORIDA. 121 

in sufficient detail to permit comprehensive statement concerning 
the fauna. 

In addition to the type locality, the Shoal River marl member 
is exposed at numerous localities in Walton County. It outcrops 
in the valleys on the west side of Choctawhatchee Kiver in the 
vicinity of Knoxhill and westward in the vicinity of Eucheeanna. 
It is also reported southwest of De Funiak Springs. A well on the 
farm of Niel Campbell near Knoxhill penetrated the following beds : 

Record of well on Campbell farm near Knoxhill. 

Feet. 

Clay, yellow, sandy 16 

Shell marl, blue (Shoal River member) 12 

Sand, white, micaceous; with many shells and some sharks' teeth 
(Oak Grove member?) 8 

36 

Fossils obtained at a depth of 33 feet from David George's well, 9 
miles southeast of De Funiak Springs, seem to show the presence of 
the marls belonging to the Shoal River member; and what is prob- 
ably the same marl is exposed on Folks Creek IJ nailes southwest 
of David George's house. The Shoal River member was discovered 
in digging a mill race, about a mile east of Argyle. At this locality 
the foUowirig section was measured by Vaughan: 

Section a mile east of Argyle. 

Feet. 

Sand, yellow, and gravel 2-3 

Sand, yellow, and clay 2 

Marl, blue, fossiliferous 3 

Other localities mentioned by Vaughan are (1) north side of the 
river,' at the head of the first draw below Shell Bluff, about 400 
yards northwest of the bluff and 200 yards from the river; (2) along 
the south side of Adams Mill Creek, near the top of a low bluff; and 
(3) on Hulion Mill Creek (sec. 7, T. 3 N., R. 21 W.). 

MIOCENE SEEIES. 

NOMENCLATURE AND SUBDIVISIONS. 

The first account of Miocene rocks in Florida was published in 1881, 
when Smith ^ made known the results of investigations carried on in 
connection with the statistical work for the Tenth Census of the 
United States. Smith's original Miocene locahty is in Orange County 
at Rock Springs, where he collected a series of fossils, identified by 
Heilprin as Miocene, from an exposure of soft limestone. Dr. Smith 
did not make any attempt to correlate the Miocene at Rock Springs 
with that at any other locality nor did he give the beds a local name. 

1 Smith, E. A., On the geology of Florida: Am. Jovir. Sci., 3d ser., vol. 21, 1881, pp. 302-303. 



122 GEOLOGY AND GROUND WATERS OF FLORIDA. 

As already noted in the discussion of the Oligocene, the term 
Miocene was used for some time to designate all the rocks in this 
region belonging stratigraphically between the Vicksburg group (then 
called Eocene) and the known Pliocene and Quaternaiy. During 
that period the Apalachicola group (upper Oligocene) was known as 
the ''old Miocene" or ''subtropical Miocene" and the true Miocene 
was discriminated by the use of such terms as "newer Miocene," 
"cold-water Miocene," or "Chesapeake Miocene." As early as 1897 
paleontologic studies ^ determined the proper correlation for the rocks 
of Oligocene age and thus left in the Miocene that portion formerly 
known as "new Miocene" or "Chesapeake Miocene." This usage is 
in accordance with the later papers of Dall.^ 

To the beds of true Miocene age Dall ^ gave the name Chesapeake 
group. This name was originally proposed by Darton ^ for Miocene 
beds of Maryland and Virginia bordering on Chesapeake Bay and 
belonging to Dana's Yorktown epoch. Chesapeake, as used by 
Darton, is the name of a formation, but it was subsequently used by 
Dall to include a number of beds which he designated the Chesa- 
peake group. 

The term Chesapeake group, as independently suggested, here includes as typical 
Barton's Chesapeake formation and also all other beds belonging to the same horizon 
and containing the same general fauna on the Atlantic and Gulf coasts of the United 

States.5 

In accordance with the usage proposed by Dall, the name Chesa- 
peak;e is a general term to include all the Miocene of the Coastal 
Plain. 

In 1894 DalP divided the "Chesapeake" of Florida into two 
formations, which he called Jacksonville limestone and Ecphora bed. 
In a subsequent paper by the same author these two divisions are 
placed together.'^ 

After the elimination of the Oligocene series from the so-called Miocene of Florida, 
we have remaining practically only one series of beds which have been identified 
over a considerable area of northern Florida. The Miocene appears as a soft Umestone 
rock in the vicinity of Jacksonville and has been traced by material from artesian 
wells on the east side of the peninsula as far south as Lake Worth. The layers of 
fossiliferous marl in the vicinity of Chipola River, at Alum Bluff, and other localities 
in western Florida are usually less than 30 feet in thickness, but counting unfossilif- 
erous clays, etc., it has been estimated that the rocks of this age in Florida may have 
attained to a thickness of some 500 feet or less. 

1 Dall, W. H., Descriptions of Tertiary fossils from the Antillean region: Proc. U. S. Nat. Mus., vol. 19, 
No. 1110, 1896, p. 303. 

2 Eighteenth Ann. Rept. U. S. Geol. Survey, pt. 2, 1898, p. 329; The Floridian Miocene: Trans. Wagner 
Free Inst. Sci., vol. 3, pt. 6, 1903, p. 1594. 

3 BuU. U. S. Geol. Survey No. 84, 1892, p. 122. 

* Darton, N. H., Mesozoic and Cenozoic formations of eastern Maryland and Virginia: Bull. Geol. Soc. 
America, vol. 2, 1891, pp. 443-445. 

6 Dall, W. H., Bull. U. S. Geol. Survey No. 84, 1892, p. 123. 
6Idem,p. 124. 

7 Trans. Wagner Free Inst. Sci., vol. 3, pt. 6, 1893, p. 1594. 



GEOLOGY OF NOETHERN AND CENTRAL FLORIDA. 123 

In Florida the limestones, clays, and sandstones of the Miocene 
are lithologically so unlike the shell marls that in the absence of 
satisfactory paleontologic evidence for their exact correlation it 
seems best to describe them separately. The two divisions are 
therefore retained, but a new name is given to the marl. The 
Ecphora bed of Dall is here called the Choctawhatchee marl from, the 
river in western Florida, where it is well exposed. At Dall's type 
locality the Jacksonville formation is known only from well records 
and excavations; hence the name is not entirely satisfactory. How- 
ever, the United States Geological Survey has decided to retain 
Jacksonville as the name of the formation, because (1) it is reason- 
ably well fixed in the literature and (2) the type faunas were collected 
at Jacksonville. The existence of exposures on Black Creek, how- 
ever, would have led to the adoption of another name if Jacksonville 
had not already been used. The samples of rock from wells on the 
east coast indicate that the limestone beds are thin and form only a 
minor part of the Miocene in that portion of the State; hence the 
word formation is here substituted for limestone. 

JACKSONVILLE FORMATION. 

The Jacksonville formation was first recognized by Dall, who 
obtained samples of the rock, together with fossils showing its age, 
from an excavation at the Jacksonville waterworks.^ 

StratigrapJiic position. — The Miocene beds lie stratigraphically 
between the underlying Oligocene and the overlying Pliocene and 
Pleistocene formations. From well records. and samples obtained 
along the east coast of Florida, the Jacksonville formation appears 
to rest unconf ormably on the eroded surface of the limestones of the 
Vicksburg group at Jacksonville, St. Augustine, and other localities. 
Farther west it probably rests on the beds belonging to the Apa- 
lachicola group" but no contacts were observed. 

Lithologic character. — When fresh the Umestone of the Jacksonville 
formation varies in color from Hght gray to nearly white; but on 
weathering it changes to pale yellow or yellowish gray. It generally 
has a porous texture but in some places is hard and dense. Much 
clear quartz sand may be easily distinguished by the use of an ordi- 
nary hand lens, and microscopic examination shows a large amount 
of clayey material that varies in color from Hght gray to pale yeUow. 
At certain horizons fossils are very abundant, but most of the shells 
have been dissolved, leaving nothing but casts or molds ; and this fact, 
together with the friable character of the rock, makes it very difficult 
to obtain satisfactory collections. However, enough material has 
been obtained to indicate the Miocene age of the rock. Urdike the 

1 BuU. U. S. Geol. Survey No. 84, 1892, pp. 124-125. 



124 



GEOLOGY AND GEOUND WATERS OF FLOEIDA. 



Choctawhatcliee marl, the Jacksonville formation appears to contain 
practically no mica. It also differs from the marl in its relatively 
higher percentage of Ume and a correspondingly lower percentage of 
sand. 

Although the Jacksonville formation is fossihferous the organic 
remains are less numerous and in a much poorer state of preservation 
than in the Choctawhatchee marl. An examination of well samples 
shows that Hmestone forms only a minor part of the formation, a fact 
well illustrated by a well at Jacksonville, in which the formation 
attains a thickness of about 500 feet and is composed largely of 
arenaceous and siliceous beds. From samples obtained in driUing a 
well at Jacksonville the clays are known to be sihceous and the hard 
materials described as gravel found to be chert nodules. Some of the 
beds consist of a hard gray sihceous rock which appears to have been 
formed by the replacement of the calcareous portion of a sandy 
Hmestone by sihca probably derived from organic remains such as 
sponge spicules and diatoms. A detailed log of the Jacksonville well 
is given below : 

Log of well at Jacksonville waterworks. 



Filled ground and sand 

Sand, varicolored, gray to red. 
Gravel . 



Rock, yellowish, fossiliferous 

Gravel; with water 

Rock, gray, fossiliferous 

Clay; with thin layers of white rock 

Clay, blue; with black gravel at 58-70 and 82-89 feet. 
Rock 



Clay, blue; with black gravel 

Rock (2 inches thick) 

Clay, blue; with quartz sand and very fine black gravel 

Clay, very hard, compact, and sand 

Clay, greenish, sandy 

Clay, greenish, sandy; with more or less black gravel and some streaks of pure clay 

Clay, sticky; with sand and fine gravel ; . 

Rock. 




Clay, greenish, sandy; with heavy gravel bed. 

Clay, blue; containing very fine sand 

Sandrock 



Shells, oysters, etc., living types 

Clay, white 

Sand, with clay enough to hold it 

Clay, compact, greenish, sandy; with streaks of nearly pure clay. 

Sand, containing shells; with just enough clay to hold them 

Shells, with scraps of fossil bone 

Coquina rock 

Clay- 



Clav, blue, and sand 

Clay, sticky, blue; very little sand 

Clay, with black gravel 

Clay, blue; with gravel and shell casts 

Clay, white; with gravel 

Marl, white; with very little sand 

Clay, light-colored 

Clay, greenish 

Clay, greenish, sandy 

Clay, sticky 

Clay; with very little sand 

Clay, nearly pure; very light when dry 

Clay, bluish, sandy; gravel and streaks of sticky clay with some nodules of rock 

Rock 

Clay, greenish; fine sand above and coarse sand below; small flow of water at 487 feet. 
Rock bowlder (siliceous concretion) in blue, sandy clay 



Thickness. 



30 
12 

58 
46 
13 

4 

15 

2 

1 

4 

4 
16 

6 
10 

1 

9 
10 

8 

7 

3 

7 
10 

5 

10 
10 
18 



27 
5 



Depth. 



Feet. 
15 
34 
34| 
40 
44 



89 
94 
100 
100 
130 
142 
204 
250 
263 
2631 
272 
287 
289 
290 
294 
298 
314 
320 
330 
331 
340 
350 
358 
365 
368 
375 
385 
390 
400 
410 
428 
434 
443 
470 
470J 
487 
492 



GEOLOGY OF NOETHERN AND CENTRAL FLORIDA. 125 

Log of well at Jacksonville waterworks — Continued. 

Thickness. Depth. 

Feet. Feet. 

Clay, compact, blue 4 496 

Clay, white 1 497 

Conglomerate rock 2 499 

Rock, hard, brownish 5 504 

Rock, very hard, compact (siliceous limestone) 6 510 

Rock, soft, white; some water 9 519 

Rock, hard, compact 5 524 

Rock, very soft, white; in layers 1 to 5 feet thick with strata of more compact rock 3 to 
12 inches thick; increase in the flow of water on breaking each hard stratum. Gaged 

flow at 632 feet, 1,000,000 gaflons in 24 hours 203 727 

Rock, compact, brown; no water 31 758 

Rock, grayish; alternate hard and soft strata; very little water 7 865 

Rock, soft, white; hard brown layers 1 to 3 feet thick every few feet; a slight increase 

of flow from each soft layer 65 930 

Rock, very hard, brown 5 935 

Rock, soft, brownish; with hard layers, flow increasing as each hard layer is broken. . 15 950 

Rock, hard and soft, in alternate layers; small increase in flow 20 970 

Rock, more compact; no water 10 980 

The sands and gravels for the first 34^ feet are probably Pleistocene^ 
though they may include some PUocene beds. 

The fossihferous Umestone at 35 feet is the Jacksonville. This 
formation may continue to a depth of at least 496 feet. 

Thickness. — Few exposures of the hmestone of the Jacksonville 
formation exceed 5 or 6 feet in thickness, though one attains a maxi- 
mum of about 15 feet 2 miles above Middleburg on Black Creek. 

Concerning the thickness of the Miocene in Florida, DaU ^ says : 

The Chesapeake group is represented over a very wide area in Florida, if the scattered 
observations already made can be regarded as indicative of its extension. Borings 
on the eastern coast of Florida and in the St. Johns Valley indicate that there the beds 
of this group in some places attain a thickness of at least 500 feet. 

Some uncertainty arises when thickness is estimated from samples of rock obtained 
from borings, and the difficulty is increased several fold when it is necessary to rely 
upon descriptions prepared by drillers. 

Information relating to the thickness of the Jacksonville formation 
on the east coast will be given in connection with the detailed sections 
(pp. 298-299); and it is only necessary here to note that Dall's esti- 
mate is probably essentially correct. Samples obtained from a well at 
Jacksonville indicate that at that locahty the formation may have a 
thickness of over 460 feet; its hmestone phase begins at 35 feet; and 
at 495 feet there was obtained a shark's tooth, which is not known to 
occur in rocks older than the Miocene. 

PJiysiograpJiic expression. — Where the Jacksonville formation hes 
near the surface characteristic sink-hole topography may exist, as at 
the original Miocene locahty near Rock Spring; but here, as in some 
other places, it is impossible to say how much of the topography is 
due to solution of the underlying porous limestone of Ohgocene age. 

Paleontologic character. — Owing to the difficulty of obtaining good 
collections the fauna of the Jacksonville formation is imperfectly 

1 Bull. U. S. Geol. Survey No. 84, 1892, p. 124. 



126 GEOLOGY AND GROUND WATERS OF FLORIDA. 

known. Dall^ reports fossils from several localities, among them 
being Peden jeffersonius, Carditamera arata, etc., from Preston sink 
3 miles north, of Waldo; and Venus rileyi, V. permagna, and Area 
limula in a well at St. Augustine at a depth of 208 feet. 

Heilprin ^ identified Pecten madisonius, Venus alveata, Venericardia 
granulata, Carditamera arata, Mytiloconcha incurva, Cardium suh- 
lineatum, and Oliva literata from E-ock Springs, Orange County. 

During the progress of the recent field work a few fossils were 
obtained from exposures on Black Creek. Though the collections 
were small, it was possible for Vaughan to determine a few species, 
which indicate the Miocene age of the rock. 

Structure, — The Jacksonville formation presents no peculiarities of 
structure and appears to have undergone no considerable disturbance 
since its deposition. Its exposures border those of the rocks belong- 
ing to the Apalachicola group and from these it dips gently seaward. 
The Miocene beds were probably affected by the general arching of the 
strata of the State, though the initial movement doubtless occurred 
before their deposition. 

Areal distribution. — On Black Creek the Jacksonville formation 
is exposed at intervals for several miles, but few exposures are more 
than 6 feet thick. On the north bank of Black Creek, about 5 miles 
above the Atlantic Coast Line Railroad, a section shows 5 feet of 
massive typical light-gray porous limestone containing a considerable 
admixture of sand and clay, ov^erlain by 6 to 8 feet of light-gray sand 
and sandy loam. The weathered surface of the limestone varies in 
color from pale yellow to buff, and, owing to the solution and removal 
of the lime, much of the weathered rock appears to be a calcareous 
sandstone. The limestone is exposed at intervals for about 2 miles 
above this locality and then gives place to Pleistocene and alluvial 
sands. Fossils are abundant in the form of casts and molds, which 
are often very beautifully preserved but are difficult to secure 
because of the friable character of the matrix. A few fossils collected 
at this locahty were identified by Vaughan as Miocene. 

About 2 miles above Middleburg, on the north bank of the creek, 
the Jacksonville formation again appears in a bluff about 25 feet 
high. 

Section about 2 miles above Middleburg on north bank of Black Creek. 

Feet. 

Loam, light gray, sandy ^ 

Sand, white (Pleistocene) 2 

Erosion unconformity. 

Clay, red, sandy 4 

Erosion unconformity. 

1 op. cit., pp. 124-125. 

Z gmith, E. A., Am. Jour. Sci., 3d ser., vol. 21, 1881, p. 303, 



GEOLOGY OF NORTHEKN AND CENTRAL FLORIDA. 127 

Feet. 
Clay, dark blue to brown, sandy; plastic when wet, granular when 

dry 4 

Unconformity. 

Limestone, soft, porous, light gray; siliceous and arenaceous limestone 

very fossiliferous, with casts chiefly of bivalve shells 10 

Limestone, soft, dense, light gray; similar to above (to water) 4 

The Miocene age of the limestone is shown by the fossils identified 
by Vaughan from the upper part of the beds. 

The Jacksonville formation is exposed at several points along the 
creek above this locality, but few outcrops exceed 3 or 4 feet in 
thickness. 

Excavations ^ at the city waterworks at Jacksonville revealed the 
presence of a yellowish siliceous limestone containing casts and molds 
of fossils, among which are Pecten jeffersonius and Carditamera. 

According to Dall ^ some of the rock at Live Oak and Lake City 
may also belong to the Miocene; but as yet this opinion lacks con- 
firmation. 

In the well at the Ponce de I^eon Hotel, St. Augustine, about 65 
miles southeast of Jacksonville, the Miocene appears to have been 
encountered at a depth of 110 feet. According to DalP the Miocene 
fossils Venus rileyi, V. permagna, and Area limula were found at a 
depth of 208 feet, while fossils characteristic of the Vicksburg group 
were obtained at 224 feet. This would indicate that the Miocene, 
which here has a thickness of 114 feet, may rest directly upon the 
Vicksburg group. 

At Rock Springs, the original Miocene exposure, the rock consists 
of a light-gray to white marly limestone, from which Smith ^ col- 
lected Peeten madisonius, Venus alveata, Venericardia granulata, 
Carditamera arata, MytiloconcJia incurva, Cardium suhlineatum, and 
Oliva literata. According to Dall, Miocene fossils were also obtained 
in a boring at Lake Worth on the east coast. 

CHOCTAWHATCHEE MARL. 

The Choctawhatchee marl includes the Ecphora bed^ and the 
aluminous clay* of Dall. The formation comprises a grayish sandy 
shell marl and gray plastic sandy clay of IMiocene age. It lies strati- 
graphically between the Oligocene and Pliocene beds and contains 
characteristic species of Miocene fossils. 

StratigrapJiic position. — According to Vaughan the Choctawhatchee 
marl rests unconformably upon the Alum Bluff formation at Alum 

1 BuU. U. S. Geol. Survey No. 84, 1892, p. 124. 
2Idem, p. 125. 

8 Smith, E. A., Am. Jour. Sci., 3d ser., vol. 21, 1881, p. 302. 

* Dall, W. H., and Stanley-Brown, Joseph, Cenozoic geology along the Apalachicola River: Bull. Geol, 
Soc. America, vol. 5, 1894, pp. 168-169. 

76854°— wsp 319—13 9 



128 GEOLOGY AND GKOUND WATERS OF FLOEIDA. 

Bluff, where the contact shows a wavy surface marked by shallow 
channels due to erosion and where the coarse light-gray sands of the 
Alum Bluff formation, which contain few fossils, change abruptly to 
the bluish-gray shell marl of the Choctawhatchee with its abundant 
fauna. Several years ago Vaughan noted similar evidence of an 
unconformity between the Oligocene and Miocene at Jacksons Bluff 
on Ochlockonee River; his section at that locality well discloses the 
relations : 

Section at Jacksons Bluffs Ochlockonee River. 

Feet. 

Sandy soil, thickness not determined 

Unexposed in slope to top of bluff face 16± 

Sands, yellow, unconformably overlying the Choctawhatchee marl 5 
Marl, yellow, sandy, fossiliferous (Choctawhatchee); greenish 

where unweathered 6^ 

(About 3 feet additional underlie the yellow sands. This bed is 
extremely fossiliferous and from it I obtained the species listed 
by Dr. Dall in his discussion of the Florida Miocene.) 
Yellow calcareous clay, the same horizon as the fuller's earth on 
land of W. W. Williams (sec. 21, T. 1 S., R. 4 W.). The upper 
surface of this stratum is extremely irregular. There are small 
channels in it; one is about 5 feet wide and more than a foot 
deep. The basal 6 to 10 inches is very largely composed of 
small pebbles and in it are embedded pieces and fragments of 
the calcareous clay. There were apparently cracks in the cal- 
careous clay and small pebbles went down into them. The 

contact is distinctly one of erosion unconformity 5^ 

Clay, stiff, bluish 6 

Sand, calcareous 6 

Limestone ledge 2 

Sands, greenish, passing beneath level of water in river 7 

54 
This section is located in the SW. | sec. 16, T. 1 S., R. 4 W., in a 

southwesterly bend of Ochlockonee River. 

The paleontologic evidence indicates a stratigraphic break between 

the Oligocene and Miocene. 

As I have on various occasions insisted, the faunal gap between the uppermost 
Oligocene [Oak Grove member] and the Chesapeake [Choctawhatchee marl] or Miocene 
is the most sudden, emphatic, and distinct in the whole post-Cretaceous history of 
our southeastern Tertiary, and indicates physical changes in the surrounding region, 
if not in Florida itself, sufficient to alter the course of ocean currents and wholly 
change the temperature of the waters on our southern coast.^ 

The relation between the Miocene and Pliocene beds of Florida 
will be discussed later. 

Lithologic character. — Lithologically the two members of the Mio- 
cene in Florida are very unlike, both in character of material and 
state of aggregation. The Choctawhatchee marl varies in color 

1 Dall, W. H. Trans. Wagner Free Inst. Sci., 1903, p. 1594. 



GEOLOGY OF NORTHERN AND CENTRAL FLORIDA. 129 

from greenish gray to light gray and consists of quartz sand contain- 
ing very large admixtures of shells and shell fragments and a smaller 
proportion of calcareous sand. In some parts of the formation the 
shells comprise a large percentage of the whole, many of them being 
ia an excellent state of preservation. Elsewhere the organic remains 
form a very subordinate part of the whole or they may be entirety 
wanting. One phase of this formation is distinctly plastic and was 
called aluminous clay by Dall and Stanley-Brown.^ 

When examined with a microscope, the marl is found to consist 
of clear quartz sand of medium fineness, coated and partly cemented 
with calcium carbonate mixed with more or less dark-colored clay. 
Calcium carbonate may be detected by the effervescence when 
treated with dilute hydrochloric acid. A certain amount of light- 
gray to nearly black material which appears in the form of a floccu- 
lent sediment in water is without doubt organic matter. In addition, 
hydrous iron oxide may be detected, generally in the form of a 
coating about the sand grains or as a stain along the cracks and on 
the exposed surfaces of the beds. It is this iron which gives some 
of the exposed surfaces a rusty color. 

Tliickness. — The Choctawhatchee marl attains a thickness of over 
50 feet in the vicinity of Redbay, Walton County, where it is exposed 
in some small ravines, and exceeds 30 feet on the banks of Mill 
Creek near Holland, in Leon County. However, from observations 
elsewhere it appears probable that the average thickness is not 
more than 25 feet to 80 feet. 

PJiysiograpJiic expression. — The Choctawhatchee marl rises to the 
surface in a belt from 6 to over 12 miles in width, extending from 
southern Walton County eastward to Leon County. Though the 
topography of this area is in part determined by the younger forma- 
tions, the influence of the soft marls is seen in the deep narrow 
v^alleys. The slopes are everywhere steep and many of the small 
streams head in springs which emerge near the upper surface of 
the Choctawhatchee marl. North and west of Crestview the surface 
is characterized by similar narrow valleys, but the marls are so 
effectually concealed by younger sands and clays that if present 
they probably have very little influence on the configuration of the 
surface. 

Paleontologic character. — The Choctawhatchee marl contains an 
abundant fauna consisting of nearly 200 species. The most numerous 
fossil is a small bivalve, Mactra congesta, which is associated with 
other mollusks, one of the most characteristic being the gastropod 
EcpJiora guadricostata. Other prominent fossils are: Conus adversa- 
rius, Fusus egualis, Crucihulum constrictum, Pecten ehoreus, Venus 

iCenozoic geology along the Apalachicola Eiver: Bull. Geol. Soc. America, vol. 5, 1894, p. 157. 



130 GEOLOGY AND GROUND WATEES OF FLORIDA. 

rileyi, Area indie, A. idonea, Oardium acute-laqueatum, 0. rohustum, 
Carditamera arata, and several species of Turritella, Dentalium, etc. 

Structure. — The Choctawhatchee marl presents no marked pecu- 
liarities of structure. It rises over 50 feet above sea level along 
its inner margin and dips gently seaward beneath the younger forma- 
tions which border the coast. Probably the formation shared in the 
slight deformation which occurred during the late Tertiary or early 
Quaternary, but the exposures are so limited that no satisfactory 
evidence of folding was observed. , 

Areal distribution. — On the west bank of Choctawhatchee River, 
about a mile southeast of Redbay, numerous exposures of bluish- 
gray Miocene marl have an aggregate thickness of probably more 
than 30 feet. The slope above the outcrops of marl is covered by 
sandy loam and shows scattered bowlders of ferruginous sandstone 
resembling the sandstones of the Lafayette (?) formation, observed 
elsewhere in Walton County and in some of the counties to the east. 
The marl at this locality is rather clayey and contains many fossils, 
which have been identified by Vaughan as Miocene. 

Miocene shell marl was encountered in a well drilled for the South- 
em States Lumber Co. near Cantonment. A complete log of this 
well was furnished by Frank Sutter, driller, but unfortunately the 
samples of material penetrated are incomplete. In a ^'greenish clay,*" 
at a depth of 500 feet, fossils were obtained, which, according to 
Vaughan's identifications, indicate the presence of beds belonguig 
to at least two geologic horizons, one being Miocene. 

Bluish-green shell marl was reported on the east bank of Holmes 
Creek, 4 miles south of Vernon, and similar material was encountered 
in a well at Millers Ferry beneath 20 feet of sand and clay. 

The Choctawhatchee marl was observed by Dall, Foerste, Vaughan, 
and others at several places on Chipola, Apalachicola, and Ochlock- 
onee rivers. The sections recorded by Dall ^ on Chipola River are as 
follows : 

The section here was measured with a steel tapeline on the left bank of Chipola 
River, Calhoun County, Fla. , at the bluff about 200 feet north of the spring, which 
here flows from a wooden pipe. 

Section at Abes Spring. 

Feet. 

1. Superficial sands, about 4 

2. Reddish and yellowish streaked sands 30-32 

3. Gray aluminous clay 19 

4. Chesapeake gray marl to water (variable) 7 

Total thickness above water 62 

1 Dall, W. H., and Stanley-Brown, Joseph, Cenozoic geology along the Apalachicola Biver; Bull. Geo!. 
Soc. America, vol. 5, 1894, pp. 160-161, 



GEOLOGY OF NORTHERN AND CENTRAL FLORIDA. 131 

In detail these strata have the following composition: 

No. 1. — Pale yellowish-gray incoherent sand, such as might be deposited by a river 
during seasons of high water; less like beach sand than the analogous material at 
Alum Bluff. 

No. 2. — Of the same character as No. 3 of Alum Bluff. The material is generally 
a little coarser and the gravels a little larger, and there is also greater heterogeneity in 
structure. 

No. 3. — Same as No. 4 (aluminous clay) of Alum Bluff. 

No. 4- — Chesapeake, just as at Alum Bluff. 

On Chipola River a mile or more north of Abes Spring, is a "slide" where timber is 
cast into the river for the construction of rafts, which are floated down the river to the 
mills at Apalachicola, on the Gulf. This place is locally known as Darlings slide, and 
is a very steep natural bank, affording an excellent section, though somewhat obscured 
by weathering and the friction of the enormous logs which are rolled over it. It is 
on the left bank, and the bank opposite is low and apparently of alluvium. 

Section at Darlings Slide. 

Feet. 

1. Superficial sands 3 

2. Reddish and yellowish streaked sands. 18-20 

3. Gray aluminous clay (presence or thickness uncertain) . ^ 



■} 



4. Chesapeake marl to water (variable) 

Total thickness above water 50 

The composition of the several beds is as follows: 

No. 1. — Pale yellowish-gray incoherent sand, such as might be deposited by a river 
during floods; less like beach sand than the analogous material at Alum Bluff. 

No. 2. — Of the same character as No. 3 of Alum Bluff. The material is generally 
coarser and the gravels a little larger. There is also greater heterogeneity in structure. 

No. 3. — The conditions were unfavorable for determining the presence or thick- 
ness of the gray aluminous clay, but from the fact that it is well exposed with sharp 
contacts at Abes Spring but a short distance south, and, together with the Chesapeake, 
makes up 27 feet of thickness, it is reasonable to suppose that it forms part of the 27 
feet assigned to Nos. 3 and 4. 

No. 4- — Chesapeake marl, in every respect the same as that formation found at 
Alum Bluff. 

It is notable that nothing below the Chesapeake is visible, although it has been 
stated that the Chipola beds exist under the gray marl. This can only be an assump- 
tion, since, with the water, as we were informed, within a foot of its lowest stage, 
nothing of the sort was visible, nor does the stream show any material such as would 
be washed out of the older Miocene beds, if present. The principal fossil here, as at 
Alum Bluff, is Mactra congesta Conrad, with which are associated Venus mercenaria L., 
and Turritella variabilis Conrad. The beds above the Chesapeake appear to be desti- 
tute of fossils. 

From DalFs discussion in an earlier part of this paper he appears to 
have regarded No. 1 of each section as Pleistocene and No. 2 as Plio- 
cene ^ and he correlates the ''aluminous clay" with the Pascagoula 
formation and the so-called "Chesapeake" (Choctawhatchee marl) 
with the Chesapeake of Virginia and Maryland, respectively. 

1 Op. cit., pp. 169 and 170. 



132 GEOLOGY AND GEOUND WATEES OP FLOEIDA. 

On the south bank of Fourmile Creek, about three-fourths mile 
north of Clarksville, the following section was observed : 

Section on Fourmile Creek, north of Clarhsville. 

Feet. 

Covered by sandy loam 30 

Clay, bluish gray, marly (plastic) 14 

Shell marl, very f ossilif erous, bluish gray (to water) 4 

The fossils observed here were the same as those which characterize 
the Choctawhatchee marl at Alum Bluff and elsewhere. Associated 
with the shells were a number of dark-colored fragments of bones 
which are locally regarded as an indication that the deposit might 
prove valuable as a fertilizer. Even though these fragments may be 
phosphatic they are not sufficiently abundant to be of economic value. 

At Alum Bluff, on Apalachicola River, the Choctawhatchee marl 
was observed by Dall. At this locality the '.'aluminous clay" is 24 
feet thick and is immediately underlain by 35 feet of sandy shell marl 
which contains an abundant Miocene fauna. There does not appear 
to have been any abrupt physical break between the fossiliferous 
shell marl and the nonf ossilif erous ''aluminous clay," though the 
latter appears to have a larger percentage of clay than the former. 
Both have the same color and both are arenaceous; but the one is 
highly fossiliferous and the other barren of animal remains, except 
for a few obscure traces of gastropods and bivalves. 

Toward the north the shell marls thin to scarcely more than 5 feet. 
On the east side of Apalachicola River, Mr. Burns ^ traced the 
Miocene marl from about 5 miles above Bristol southward for about 
13 miles to the place where it finally disappears. 

The Choctawhatchee marl is exposed at numerous points on 
Ochlockonee River. About 16 miles west of Tallahassee (sec. 9, 
T. 1 S., R. 2 W.) Vaughan found an exposure of Miocene marl. The 
outcrop is on Duggar Creek nfear the house of W. C. Allen; the mate- 
rial contains the same fauna and is lithologically similar to the 
Choctawhatchee marl at Alum Bluff. 

On the farm of J. R. Harvey, a mile west of Holland, a bed of very 
fossiliferous marl was encountered in a well at a depth of 28 feet. The 
section is : 

Well section 1 mile west of Holland. 

Feet. 

Sand, red, ferruginous 10 

Clay, red and yellow, sandy 8 

Marl, yellow, becoming bluish gray below the surface (Choctaw- 
hatchee) ; water bearing 7 

A few fossils from the material obtained from this well, identified by 
Vaughan, show the age of the marl to be Miocene. 

1 BuU. U. S. Geol. Survey No. 84, 1892, p. 124. 



GEOLOGY OF NORTHEEN AND CENTRAL FLORIDA. 133 

Near Block's sawmill, on the banks of Mill Creek, the Choctaw- 
hatchee marl is more than 30 feet thick, but the exposures are poor. 
The material in the bed of the creek ranges from blue to yellowish 
gray in color and is not fossiliferous, but an exposure of about 5 feet 
of bluish-gray shell marl about 25 feet above the stream contains 
fossils. A small collection obtained from this bed shows the Miocene 
age of the marl. 

About a mile southwest of Holland similar shell marl was encoun- 
tered in digging a mill race at Hugh Black's sawmill. According to 
statements made by James R. Harvey, this shell marl extends south- 
ward along Ochlockonee River nearly 12 miles. At Jacksons Bluff, 
about a mile southwest of Bloxham, the Choctawhatchee marl is 8 to 
10 feet thick. This locality was described in 1894 by Dall,^ and the 
locality was visited in 1900 by Vaughan, who collected the fossils 
listed by Dall ^ in his discussion of the Florida Miocene. 

Vaughan also collected from a yellowish sand representing a slightly 
higher stratum of the same bluff (NE. i sec. 20, T. 1 S., R. 4 W.) ; he 
reports the occurrence of similar fossils in sections 21 and 30. 

The presence of Pecten madisonius in a collection of Pliocene fossils 
from the banks of St. Johns River one-fourth mile below Nashua, 
Putnam County, suggests that Miocene may occur at that locality. 
The collection was made from a shell marl forming a bluff which rises 
about 3 feet above the river. 

Samples of marl from a well at De Land were found by Vaughan to 
contain Pecten (type of madisonius) and Chione (type of cancellata). 
From the presence of the madisonius type of Pecten the marl is 
believed to be Miocene. 

Species of Pecten eboreus and Pecten gihhus, together with Ostrea 
Mitiensis Sowerby, are also found about a mile above Caloosa on 
Caloosahatchee River. The presence of these fossils may indicate 
that the beds are Miocene; but this conclusion is held subject to 
revision in case subsequent investigations should result in the finding 
of larger collections belonging to some other period. This locality, 
should it be Miocene, is of special interest because heretofore no 
Miocene has been reported so far south on the Gulf coast of the 
State. t 

PLIOCENE SERIES. 

The Pliocene of Florida comprises the Caloosahatchee marl, the 
Nashua marl, the Alachua clay, and the Bone Valley gravel. Only 
the Alachua clay is considered to be a land deposit, the others being 
supposedly of marine origin. 

1 Dall, W. H., and Stanley-Brown, Joseph, Cenozoic geology along the Apalachicola River: Bull. Geol. 
Soc. America, vol. 5, 1894, p. 158. 

2 Trans. Wagner Free Inst. Sci., vol. 3, pt. 6, 1903, pp. 159fr-98. 



134 GEOLOGY AND GBOUND WATERS OF FLORIDA. 



CALOOSAHATCHEE MARL. 



Nomenclature. — ^Pliocene beds were recognized in Florida as early 
as 1885, but the first published account of them is found in Heil- 
prin's report, issued in 1887.^ This writer gives a description of the 
shell marls exposed along Caloosahatchee Kiver and states that 
they are of Pliocene age. He says: 

It will thus be seen that the relation of recent to extinct species is as 48 to 41, giving 
a very much higher percentage for living forms than obtains in any of the divisions 
of our recognized Miocene deposits, even the ''Carolinian," which holds a position 
nearly equivalent to the so-called Mio-Pliocene of Europe. It becomes manifest 
that this most extensive Floridian exposure represents the Pliocene age — a circum- 
stance interesting, apart from the general bearing which its presence has upon the 
geology of the State in particular, from the fact that it gives us the first unequivocal 
indication of the existence of marine Pliocene deposits in the United States east of 
the Pacific slope. 

To the beds described Heilprin ^ gave the name Floridian. The 
name Caloosahatchee marl was applied by Dall to the Pliocene 
beds along Caloosahatchee River and the streams entering Char- 
lotte Harbor.^ In 1887 the shell marls on Caloosahatchee River 
were described by Dall,* who agreed with Heilprin in referring them 
to the Pliocene. In subsequent papers ^ by the same author these 
marls were called the Caloosahatchee beds, from the type locality 
on the river of that name. Thus DalFs Caloosahatchee beds include 
the Floridian beds of Heilprin. The name proposed by Dall is 
retained for the Pliocene beds of Caloosahatchee River and neigh- 
boring streams, but as these beds are largely marl the formation 
is here called Caloosahatchee marl. 

The type locality of the so-called '' Arcadia marl"® is on Mare 
Branch, a tributary of Peace River, about 6 miles north of the town 
of Arcadia, and with this marl is included an oyster marl which 
Dall described from a locality about 3 miles north of the wagon 
bridge at Arcadia.'^ The close resemblance of this marl to the 
Caloosahatchee marl seems to warrant regarding it as a phase of 
that formation, thus making the term ''Arcadia marP' superfluous. 

StratigrapJiic position, — ^The contact of the Caloosahatchee marl 
with the underlying Miocene has not been observed, but the faunas 
show a considerable difference, probably due to physiographic 
changes which permitted the erosion of the Miocene beds before the 
beginning of the Pliocene deposition. The contact of the Caloosa- 
hatchee marl with the overlying Pleistocene is commonly marked 

1 Trans. Wagner Free Inst. Sci., vol. 1, 1887, pp. 26-33. 

2 Idem, p. 32. 

3 Dall, W. H., Notes on the geology of Florida: Am. Jour. Sci., 3d ser., vol. 34, 1887, p. 169. 
* Idem, pp. 161-170. 

6 Bull. U. S. Geol. Survey No. 84, 1892, pp. 140-149; Trans. Wagner Free Inst. Sci., vol. 3, pt. 6, 1893, 
pp. 1603-1605. 

« Bull. U. S. Geol. Survey No. 84, 1892, pp. 131-132. 

7 Idem, pp. 132-133. 



GEOLOGY OF NOBTHERN AND CENTRAL FLORIDA. 135 

by an erosional unconformity. Where this unconformity is not 
noticeable it may have been obscured by the reworking of the Pliocene 
marl by the waves of the Pleistocene sea. 

Lithologic character. — The Caloosahatchee marl consists of a light- 
gray shell marl, in many places interbedded with nearly pure sand. 
The matrix is generally very calcareous but locally it consists of 
sand, and even in the most calcareous portion sand is abundant. 
The shells are remarkable for their excellent state of preservation 
and their abundance in certain layers makes it possible to secure 
large collections. 

Thickness. — It is difficult to correctly estimate the thickness of 
the Caloosahatchee marl, but its maximum is probably at least 25 
feet. Few single exposures exceed 5 to 10 feet, and the average 
thickness is probably less than 8 feet. On the whole the Caloosa- 
hatchee marl is a thin deposit, though it may thicken considerably 
toward the central portion of the peninsula and toward the southern 
end of the State. 

Physiographic expression. — The Caloosahatchee marl occupies a 
region of such low altitude that it has been only slightly dissected. 
In fact with the exception of the valleys of the streams entering 
Charlotte Harbor the surface of the region underlain by this forma- 
tion is an almost unbroken plain. Though this is in part due to the 
later deposit of Pleistocene sand, it is doubtful if the surface of the 
Caloosahatchee marl has ever suffered extensive erosion. 

Paleontologic character. — Dall's list of Pliocene fossils obtained from 
the Caloosahatchee marl in Florida includes 639 species, of which 
256 species are not known from other States. The marine forma- 
tions of this period are very fossiliferous, and the fauna as a whole 
is such as might be expected in shallow water. Dall ^ notes that the 
upper beds of the Caloosahatchee Pliocene contain a fauna more 
closely related to living forms than the lowermost layers, and that 
the shoaling of the water permitted the formation of oyster reefs and 
the final influx of fresh-water species of Planorbis, etc. 

Structure. — The dip of the Pliocene beds in Florida is usually very 
difficult to determine. Caloosahatchee River crosses the Caloosa- 
hatchee marl at the type locality and thus affords a good opportu- 
nity for observing the attitude of the marl beds. Dall ^ says: 

The uppermost strata of the Pliocene beds begin to appear above the level of the 
river at low water (during the dry season) about 24 miles due east from the shore of 
Charlotte Harbor, and they dip to the eastward out of reach about 30 miles farther 
east. Their total measured breadth here is thus at least 30 miles and includes the 
whole of the elevated land between Lake Hicpochee and the point on the river above 
mentioned. In this distance there are not less than 20 visible but very gentle folds 
of the strata in the direction of the trend of the peninsula. 

1 Bull. U. S. Geol. Survey No. 84, 1892, pp. 145-146. 

2 Idem, p. 146. 



136 GEOLOGY AND GROUND WATERS OF FLORIDA. 

In a later paper Dall says : ^ 

The Pliocene beds dip gently to the westward so that those portions near the sea 
are newer than those outcropping near the headwaters of the streams. 

In the discussion of the Miocene rocks the marls near Caloosa were 
doubtfuUy referred to that epoch. The Caloosahatchee marl is 
exposed at intervals from near Caloosa to the vicinity of Labelle, 
several miles farther upstream, where the Pleistocene appears. The 
relation of the Pliocene and the Pleistocene here may be interpreted 
by supposing an easterly dip of the beds. The alternative hypothe- 
sis of a westerly dip could only be true if the increase in altitude of 
the water surface were somewhat greater than the thickness of the 
Caloosahatchee marl. The actual rise in water level between Caloosa 
and Labelle as determined instrumentally varies with the stage of 
the river, but at mean low water is probably less than 5 feet. The 
actual dip of the beds is probably easterly instead of westerly. 

Aside from a slight tilting the marls of Caloosahatchee River have 
been gently folded so that they exhibit a series of low undulations 
with axes parallel to the general trend of the peninsula. These arches 
are usually less than one-fourth mile wide, and they probably do not 
exceed 15 feet in height. Elsewhere no folding has been observed; 
but it is probable that the disturbance which produced the low arches 
on the Caloosahatchee was general and that the other Pliocene beds 
may exhibit the same structural features. 

Areal distribution. — Exposures of the Caloosahatchee marl are 
numerous on Caloosahatchee River between LabeUe and Caloosa. 
Of this Pliocene rock Dall ^ sa3^s : 

On the Caloosahatchee the strata may be divided into oyster-reef marl beds, con- 
chiferous or Turritella marl, and layers of sand, which intergrade without distinction 
and have no invariable succession but always grade into the shallow- water fauna at 
the top, which is overlain by the Planorbis rock, and this in turn by post-Pliocene 
deposits which are seldom of great thickness. 

At LabeUe the Caloosahatchee marl, consisting of 4 feet of cal- 
careous sand containing a large number of Pliocene shells, lies beneath 
3 feet of fossiliferous Pleistocene marl, which in turn underUes 3 feet 
of sandy loam. A mile below Labelle the following section was 
observed: 

Section on Caloosahatchee River 1 mile below Labelle. 
Recent: Feet. 

Surficial soil and muck 3 

Pleistocene or recent: 

Marl, banded, varying from nearly black to yellow 1 

Caloosahatchee marl: 
Marl, gray, clayey, containing some nodules; very fossiliferous. . . 4 
Marl well stratified, greenish gray, clayey, containing some fossils. 2 

10 

1 Trans. Wagner Free Inst. Sci., vol. 3, pt. 6, 1903, p. 1604. 
a Bull. U. S. Geol. Survey No. 84, 1892, p. 147. 



GEOLOGY OF NOETHERN AND CENTRAL FLORIDA. 137 

One-half mile below the last locality the Caloosahatchee marl is 
about 7 feet thick and is abundantly fossiliferous, containing many 
large pectens, ostreas, and gastropods. About a mile farther down- 
stream a conspicuous oyster bed about a foot thick rises above the 
level of the river. Five miles below Labelle the following section 
was examined: 

Section on Caloosahatchee River 5 miles below Labelle. 

Feet. 

Marl, concretionary calcareous; very fossiliferous 3 

Oyster bed characterized by large Ostrea sculpturata and Pecten ehor- 

eus 2 

Marl, soft, white, clayey * 4 

9 
The oyster bed is exposed at intervals for several miles. 
In addition to the exposures of Caloosahatchee marl already 

described Dall mentions several localities on other streams entering 

Charlotte Harbor : ^ 

Near the north end of Charlotte Harbor a small creek comes in from the east called 
Alligator Creek. Here Mr. Willcox found an extension of the Caloosahatchee beds. 
The banks are about 12 feet high, the upper half being pure sand; the lower half 
contains fossils of Pliocene age, mollusks, barnacles, and flat Echinidae. They differ 
from the Caloosahatchee deposits in being in pure sand instead of marl as a matrix. 
The upper half of the fossiliferous stratum shows the shallow-water fauna, with its 
usual partial admixture of strictly Pliocene extinct species. Some parts of the bed 
are united by siliceous cementation into a hard rock. * * * The banks are higher 
here than on the Caloosahatchee, being 25 feet at the highest point, but the difference 
is chiefly of unfossiliferous marine sand 12 feet deep. Then comes about 2 feet of 
shallow- water fauna with some Pliocene species, below which is a hard limestone 
stratum 2 or 3 feet thick, beneath which is a bed of conchiferous marl like that of the 
Caloosahatchee. There are slight differences in the fauna, such as might be expected 
at points 20 miles apart. * * * 

Here [on Miakka River] Mr. Willcox found a bed of limerock at the sea level with 
uncharacteristic species poorly preserved. Above the limerock are beds of shell marl 
considerably mixed with sand. In this deposit was collected about 40 species of 
shells, of which about 10 per cent were extinct Pliocene species. This bed seems to 
have fewer extinct species than the Caloosahatchee marls and may be regarded as a 
little younger, perhaps corresponding to the Planorbis rock, which seems to be absent 
on the Miakka. 

Along Rocky Creek, which falls into Lemon Bay near Stump Pass, in about latitude 
26° 55^ west from the Miakka, a bed of Veniis cancellata rises to about a foot above the 
water, or in many places forms the bed of the stream. It is probably the upper 
shallow-water layer of the Pliocene, as Cerithidea scalata Heilprin, a Pliocene species, 
has been found near by on the beach of the bay. 

On Peace Creek there are no banks high enough to afford a section, and no trace of 
Pliocene yet observed up to 3 miles above Fort Ogden. 

Farther north, on Peace Creek, the Caloosahatchee beds appear at Shell Point, 3 
miles above Arcadia, as previously described; and I was informed that the same bed 
occurs on Joshua Creek, near Nocatee, and at a point on Peace Creek 6 miles below the 
works at Arcadia, between that place and Fort Ogden. The same oyster bed is con- 

1 Bull. U. S. Geol. Survey No. 84, 1892, pp. 147-148. 



138 GEOLOGY AISTD GEOtTl^^D WATEBS OF FLOEIDA. 

spicuous in the banks of a small stream just north of the railroad station at ZoKo Springs. 
This stream, a feeder of Peace Creek from the east, has cut quite a deep gully, and the 
oyster bed occurs in the vertical sides about 2 feet, or possibly less, above the water 
when the latter is low, as in January, when I observed it. Above the oyster bed the 
elevation cut by the stream is composed of some 20 or 25 feet of yellow sand, with a 
foot or two of the white sand covering it. Some portions of the yellow sand here, as at 
Shell Point, are quite indurated and stand vertically like rock. The section can be 
well observed from the railway culvert. 

Considerably east of Peace Creek beds of marl containing "large clams" have been 
reported to Mr. Willcox as occurring on the banks of Arbuckle Creek. Something of 
the same sort on the Kissimmee River, near Fort Kiesimmee, was mentioned to me by 
prospectors at Bartow who had visited that locality. Both these marl beds are likely 
to prove to be Pliocene. 

The oyster marl which occurs on Peace Creek about 3 miles above 
Arcadia has been correlated with the Caloosahatchee marl.^ Dall's 
section is : 

Section on Peace Creeh 3 miles above Arcadia. 

Feet. 

1. Humus and white sand 3-5 

2. Yellow sand (indurated) 3 

3. Oyster marl (in part subaqueous) 2-4 

Nos. 1 and 2 of this section are doubtless Pleistocene. 

Dall ^ gives the following section of the '^ Arcadia marl/' which he 
considers to be slightly older than the Caloosahatchee: 

Section of ^^ Arcadia marV^ at edge of Peace Creeh. 

Feet. 

Humus and white sand 1^ 6 

Yellow sand 6 -10 

"Peace Creek bone bed" phosphatized rock with bones (about), . 1 

ryellowish sandy marl to water's edge 3 

Arcadia marlj^j^^ ^^^^ ^^^^^ ^^^^^ (about) 3-6 

The ''Peace Creek bone bed" is probably to be correlated with the 
Alachua clay, and the first and second members of the section are 
doubtless Pleistocene. 

NASHUA MARL. 

Discrimination. — ^During the progress of the field work for this 
report, fossils were collected which indicate that Pliocene marls are 
extensively developed along the valley of St. Johns River. These 
beds possess certain faunal elements which distinguish them from 
the other Pliocene beds of Florida and are given a distinct name — the 
Nashua marl — ^from a locality on St. Johns River where they are best 
exposed. Further study may result in uniting all of the marine 
Pliocene of Florida under a single name; but for the present it 
appears desirable to avoid hasty correlation by the use of local 
names for the beds of different localities, especially where conditions, 
governing deposition appear to have been tmlike. 

» Bull. U. S. Geol. Survey No. 84, 1892, p. 132. 2 idem, p. 131. 



GEOLOGY OF NORTHERN AND CENTRAL FLORIDA. 139 

StratigrapJiic position. — The Nashua marl is thought to rest uncon- 
formably on the Miocene at De Land, but this opinion lacks confir- 
mation, as the fossils from that locality have not been studied in 
sufficient detail to determine the exact age of the beds. At several 
localities the contact between this formation and the overlying 
Pleistocene sand has been observed and it is everywhere marked by 
distinct unconformity. The Pleistocene beds rest upon an undu- 
latiQg surface, clearly due to erosion, of Nashua marl, and the con- 
trast between the fossiliferous marl and the overlying barren sands 
helps to emphasize the break between the two. (See PL XI, A, B.) 

Lithologic character. — The Nashua marl bears a strong lithologic 
resemblance to the Caloosahatchee marl, showing the same alterna- 
tion of sand beds with shell marl. The matrix of the Nashua marl, 
though calcareous, is everywhere more or less sandy and in places con- 
sists of nearly pure sand. The shells are generally well preserved, 
though locally marls consisting of broken and eroded fragments of 
shells are not uncommon, and it is easy to obtain good collections of 
fossils. 

TJiicTcness. — ^The Nashua marl, the only Pliocene formation in the 
area of its occurrence, is much thinner than the underlying Miocene 
strata. This fact, together with its distribution beneath the lowlands 
near the coast, indicates that the Pliocene submergence in northeast- 
ern Florida was less prolonged than the Miocene ; and the presence 
of shallow-water fossils shows that the Pliocene sea did not attain 
any great depth over that part of the State where the marine beds 
are now exposed. The Nashua marl is in few places more than 6 or 
8 feet thick, but locally it attains a greater thickness. Samples from 
a well at De Land indicate that there the Nashua marl is about 32 
feet thick. 

Physiographic expression. — The Nashua marl occupies the St. 
Johns Valley, where it underlies a broad terrace bordering the stream. 
It probably occurs beneath the plain east of St. Johns River, but the 
overlying Pleistocene forms a mantle so thick that the Nashua marl 
has no effect on the topography and appears not to outcrop. 

Paleontologic character. — ^The fauna of the Nashua marl is imper- 
fectly known, but it has been sufficiently studied to show that it 
resembles that of the Caloosahatchee marl. The most striking 
difference between the faunas of the two formations is the existence 
of certain species in the Nashua marl which occur in the Waccamaw 
fauna of the Carolinas but are not known to be present in the Caloosa- 
hatchee marl. This affinity with the fauna to the north suggests the 
existence of a cold current along the Atlantic coast which permitted 
asouthward migration of the Waccamawfauna. Thelackof exposures 
in the central portion of the peninsula prevents the tracing of the 



140 GEOLOGY AND GROUND WATERS OF FLORIDA. 

connection between the two formations and the determination of the 
limits of the southward movement of this current of cold water. 

Structure. — The Nashua marl is exposed at only a few localities in 
the St. Johns Valley and it is difficult to form any definite idea con- 
cerning its structure. It has probably been subjected to the same 
deformation as the Caloosahatchee marl, but its isolated exposures 
afford no evidences of folding. The dip is doubtless seaward and is 
probably very slight. 

Areal distribution. — In the St. Johns Valley the Nashua marl is 
exposed in many places. At the type locality, one-fourth mile south 
of Nashua, Putnam County, 5 feet of white sand is exposed, resting 
unconformably upon about 15 feet of white shell marl. From this 
locality fossils were obtained which Vaughan identified as Pliocene, 
though the presence of Pecten madisonius suggests that there are also 
Miocene beds in the exposure. 

One-half mile above the Atlantic Coast Line Railroad bridge over 
St. Johns River in Putnam County, in a bluff which rises 3 to 8 feet 
above high water, the Pliocene (Nashua marl) is well exposed and 
abundantly fossiliferous. The age determination of the fossils is by 
Vaughan. 

About one-half mile south of De Leon Springs in Volusia County 
the following section was examined : 

Section one-half mile south of De Leon Springs. 

Feet. 

Sand, white (Pleistocene or Recent) 4 

Unconformity. 

Sand, yellowish brown, and clay; unassorted near the top, but 

grading downward to well-stratified clay (Pleistocene) 7 

Unconformity. 

Shell marl, yellow to white (Nashua marl) 6 

17 

At one place the clay extends downward into the Pliocene marl 
in a channel 2 feet across and 4 feet deep. 

The names of a few fossils obtained from this locality are given by 
Dall.^ His list contains Orepidula aculeata Gmelin, Ostrea sculp- 
turata Conrad, Carditamera arata Conrad, and Mulinia congesta 
Conrad. 

This list includes only four species, of which the first {Crepidula 
aculeata Gmelin) is marked by an asterisk in Dall 's table to indicate 
that it is believed to survive to the Recent fauna. Of the other 
three, one, Ostrea sculpturata,^ is known from the Florida Pliocene 
of Caloosahatchee River, Alligator Creek, and Shell Creek, and 

1 Trans. Wagner Free Inst. Sci., vol. 3, pt. 6, 1903, pp. 1596-1598. 

2 Idem, pp. 1605-1614. 



U. S. GEOLOGICAL SURVEY 



WATER-SUPPLY PAPER 319 PLATE XI 




A. CONTACT OF NASHUA MARL AND PLEISTOCENE SAND A QUARTER OF A MILE BELOW 
NASHUA, ON ST. JOHNS RIVER. 




B. CLAY UNCONFORMABLY OVERLYING NASHUA MARL IN PIT ABOUT HALF A MILE 
SOUTH OF DE LEON SPRINGS STATION. 



GEOLOGY OF NOETHERN AND CENTRAL FLORIDA. 141 

another, Oarditamera arata, is known from the same beds and from 
the Pliocene fauna of the Waccamaw formation of the CaroHnas. 
This leaves' but one species, Mulinia congesta, of Dall's list which is 
not known from the Florida Pliocene. This species is not known to 
occur in beds younger than the Miocene, and hence the exposure was 
called Miocene by Dall. A much larger collection was made during 
the progress of the field work and according to Yaughan's identifi- 
cation there are Pliocene beds in the exposure. 

On the east side of St. Johns River, about 5 miles north of the 
Atlantic Coast Line Railroad bridge in Volusia County, there is a 
low exposure of sandy loam, sand, and marl. The upper member 
consists of about 2 feet of light-colored sandy loam which passes by 
gradual transition into a coarse-grained gray sand. Beneath this 
sand and probably separated from it by an unconformity is a bed of 
light-green clayey marl containing many well-preserved shells. A 
collection of fossils was obtained. The presence of Cardium wdalium 
has led to the inference that the marl is of Pliocene age. 

About 300 yards farther north and on the same side of the river 
the marl is in some places unconformably overlain by a thin bed of 
gray limestone and in other places by partly indurated sand. The 
limestone is probably of Pleistocene age. About 2 miles north of 
the first locality an exposure of shell marl one-half foot thick is 
capped by a deposit of clay and sand which is probably alluvial. 
From this locality a few species were obtained, and Vaughan regarded 
the beds as '^ probably Pliocene." 

From a well near Kissimmee, Vaughan obtained fossils that not only 
serve to indicate the presence of Pliocene beds but also show that 
they are buried beneath at least 96 feet of Pleistocene sand and marl. 

ALACHUA CLAY. 

Deposition. — The nonmarine Alachua clay has usually been 
regarded as Pliocene, and it appears to be a terrestrial or fresh-water 
deposit. 

This formation was described by Dall ^ in 1892: 

Later in this essay I shall endeavor to indicate all that is known to date of writing 
of the marine Pliocene beds of Florida, but there is another fojrmation to be spoken of 
which has been referred by some authorities to the upper Miocene, though regarded 
by others as late Pliocene or even Pleistocene. This comprises the deposits of clay 
containing bones of extinct Mammalia which, in my report to the Director of the 
United States Geological Survey in 1885, I termed the Alachua clays. 

The report mentioned above does not appear to have been pubUshed, 
and hence the quotation probably contains the first pubUshed refer- 
ence to these clays. With these beds is included the Peace Creek 

iBuU. U. S. Geol. Survey No. 84, 1892, p. 127. 



142 GEOLOGY AND GROUND WATERS OF FLORIDA. 

bone bed of Dall/ which appears to consist of eroded and redeposited 
material derived from an older deposit. 

Stratigraphic position. — ^The Alachua clay is known to occupy sinks 
and gulUes in the Oligocene and probably also in the Miocene beds. 
Observations made by Dall along the banks of Peace Creek show that 
a bone bed ('^Peace Creek bone bed"), which he correlates with the 
Alachua clay, rests upon older Pliocene beds.^ The Alachua clay 
and the '^ Peace Creek bone bed" have not been observed in contact, 
but they are believed to be lacustrine or fluviatile deposits formed at 
different times. The Alachua clay is also thought to be contempora- 
neous with a part of the Caloosahatchee and Nashua marls. , 

Lithologic character. — The Alachua clay consists of blue to gray 
sandy clay which weathers to light yellow or red from the presence 
of iron oxide. It generally contains sufficient clay to give it distinct 
plasticity but also commonly contains sand in considerable quanti- 
ties. The weathered material is frequently more or less concre- 
tionary as a result of the aggregation of the iron oxide. The forma- 
tion is nearly destitute of fossils except in a few localities where it 
is filled with vertebrate remains. 

Thiclcness. — ^The Alachua clay represents accumulations in depres- 
sions of the surface of the OKgocene beds, and hence its thickness is 
variable, being known to reach 15 feet and possibly much more; its 
average is probably not less than 10 feet. 

Physiographic expression. — The Alachua clay has no marked effect 
on th3 topography, but by its accumulation in depressions in the 
underlying rocks it probably helps to diminish the relief. Locally it 
is represented by low ridges which rise above the general level. 

Paleontologic character. — The Alachua clay contains a few obscure 
remains of what appear to be fresh-water shells, in a state of preser- 
vation that does not permit their identification. Locally, verte- 
brate remains are abundant, and it was this fauna which first called 
attention to the formation. 

At the request of the senior author of this report. Dr. J. W. Gidley, 
assistant curator of the United States National Museum, made a 
study of the lists of fossils from the Alachua clay and the ^^ Peace 
Creek bone bed." His report is given below: 

Notes on the relative ages of the beds at Archer, at Mixon's, and at Ocala, Fla., and 
their correlation with deposits of the western-plains region. 

The faunas of the beds at Archer and Ocala indicate two distinct horizons, the latter 
being much the newer. With the possible exception of Elephas columhi from the beds 
at Ocala and the " Peace Creek beds, ' ' none of the Florida horizons contain any species 
in common with beds of the western-plains region, hence an accurate estimate regard- 
ing the relative age of these beds with those of the west is not possible at the present 
time. 



1 Bull. U. S. Geol. Survey No. 84, 1892, pp. 130-131. 



GEOLOGY OF NORTHERN AND CENTRAL FLORIDA. 143 

The presence of Elephas and true Equus, as well as specimens referred to Bison, 
Cervus, and Megalonyx, in the beds at Ocala and in the "Peace Creek beds," suggest 
Pleistocene for these horizons, although they may just as well be late Pliocene. 
Judging from the less-advanced stage of development of these species, these beds 
seem to be older than the beds at Hay Springs, Nebr., which have been considered 
to be deposited near the beginning of the Pleistocene, and may be about the equivalent 
of the deposits of Loup River, Nebr., which are held to be either late Pliocene or 
early Pleistocene. 

The beds at Archer and at Mixon's contain a fauna which in point of development 
seems to correspond closely with that of the " Republican River formation" of Kansas 
and Nebraska, thus bringing them near the dividing line between the Miocene and 
Pliocene, and they may be, with good reason, placed in either the upper Miocene 
or lower Pliocene. 

The horses are represented by Miocene genera, but the species seem in general to 
be more highly specialized. This does not necessarily mean a later phase or horizon 
but suggests it. 

From the evidence furnished by vertebrate fossils, therefore, it may be concluded 
that the beds at Archer and those at Mixon's, 10 miles east of Archer, are in age near 
the transition from the Miocene to the Pliocene and that the newer beds at Ocala and 
Peace Creek, Fla., may be placed in time very near the beginning of the Pleistocene. 

Gidley's report was made since the preparation of the manuscript 
for this paper, and it is incorporated here without attempting to place 
the discussion of these beds in separate sections of the report. The 
topographic position of the Alachua clay suggests that it may be 
Miocene. The fossils identified from Ocala came from the depressions 
in the surface of the limestone at the quarry of the Ocala Lime Co.. 
The topographic position of the ''Peace Creek bone bed" is such that 
it might be either Pliocene or Pleistocene, for it lies near the present 
water level of the stream and may be either an older formation ex- 
posed by erosion or a Pleistocene deposit made in the valley. 

Structure. — The Alachua clay appears to have undergone no 
marked disturbance since its deposition and hence presents no 
structural featiires of interest. Its accumulation in local depressions 
prevents its having any general attitude; the dips observed are 
slight and variable. 

Areal distribution. — Sections of the Alachua clay are to be seen in 
the vicinity of Gainesville and Archer, in Alachua County. In an 
exposure in an old mill race, a mile northwest of Gainesville, the out- 
crop probably does not exceed 4 feet; but farther up the hill to the 
east 15 feet of similar material, which is overlain unconformably 
by about 4 feet of white sand, is exposed in a ditch. The basal 
portion of the section, which evidently represents one of the localities 
mentioned by Dall,^ is a greenish-blue clay containing a large 
admixture of coarse sand. It changes to a very light yellow when 
exposed to the weather, and in this respect agrees with the material 
on the hillside above. 

1 Bull. U. S. Geol. Survey No. 84, 1892, p. 128. 

76854°— wsp 319—13 10 



144 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

The complete section at this locality is: 

Section a mile northwest of Gainesville. 

Feet. 

Sand, light gray 4 

Erosion unconformity. 

Clay, greenish blue, sandy; weathering light yellow 15 

Covered , 15 

Clay, greenish blue, sandy '. 4 

38 

About 2 J miles west of Gainesville another exposure of Alachua 
clay consists of a light-yellow clayey sand which is very plastic 
when wet but hardens into a moderately firm rock on drying. The 
outcrop is not less than 15 feet thick and is covered by a deposit of 
sandy loam of Pleistocene age, which rests unconformably on the 
clays. Thin partings of sand are common; the upper 4 feet of the 
section contains many small calcareous nodules, and near the middle 
some casts of what appeared to be fresh-water bivalves. 

Dall ^ mentions the occurrence of vertebrate remains on Peace 
Creek, Caloosahatchee Eiver, and in Wakulla County. He also 
gives the following list of localities for the Alachua clay: 

Among the localities to be noted are: In Alachua County, Mixon's farm, 10 miles 
south and IJ miles east of the railway station at Archer; Hallo well's place, 10 miles 
north and 2 miles west of the station; a pond about one-fourth of a mile from the 
station; another in the vicinity of Mixon's, 2 miles northwest of the first; a ditch 
about 2^ miles west of Gainesville; a spot where the railway crosses Santa Fe River, 
near Gainesville; 1 mile north of Gainesville, on the Newnansville road, in a ditch 
dug for a mill race; and Owen's, nearer the town. Other localities are: Clay Landing, 
on the Suwannee River, near Fort Griffin, Levy County; Rocky Creek (old Tampa 
Bay), Hillsborough County {Bison latifrons); Phillips quarry, Ocala, Marion County. 

BONE VALLEY GRAVEL. 

Nomenclature. — The deposits here called Bone Valley gravel have 
been described by both Eldridge ^ and Dall.^ They comprise nearly 
all of the pebble phosphates now being mined in Florida, the name 
behig derived from a locality west of Bartow, where the beds were 
worked on a large scale. Different names were formerly used for 
this formation by different writers, Eldridge designating the deposits 
land-pebble phosphates and Dall calling them simply pebble phos- 
phates. Both writers distinguish between the Tertiary deposits of 
Pliocene age and the younger pebble phosphates, which range in age 
from Pleistocene to Eecent. 

The general character of this formation, with its rounded pebbles 
and good stratification, shows that it is of subaqueous origin, and the 

1 Bull. U. S. Geol. Survey No. 84, 1892, p. 128. 

2 Eldridge, G. H., Preliminary sketch of the phosphates of Florida: Trans. Am. Inst. Min. Eng., vol. 
21, 1893, pp. 196-231. 

3 Dall, W. H., and Harris, G. D., Ccrrelation papers— Neocene: Bull. U. S. Geol. Survey No. 84, 1892, 
pp. 137-138. 



GEOLOGY OF NORTHERN AND CENTRAL FLORIDA. 145 

presence of marine and land vertebrate remains indicates that it 
was deposited in a shallow sea. The shallow-water origin of these 
beds is also shown by the many alternations of coarse and fine 
material and by the lenticular character of many of the beds. 

StratigrapJiic position. — The Bone Valley gravel rests on an eroded 
surface of the Alum Bluff formation. The overlying Pleistocene 
sands, where present, rest on an uneven surface of the Bone Valley 
gravel, and though the surface of the gravel and associated sands 
does not appear to be very irregular, the widespread character of 
the unconformity indicates that the interval between the deposition 
of the Pliocene and Pleistocene was marked by erosion. The exact 
correlation is somewhat uncertain, but the Bone Valley gravel is 
believed to be older than the upper beds of the Caloosahatchee marl. 
It is probably in part contemporaneous with the Alachua clay and 
may therefore be upper Miocene. This is inferred from the fact 
that the two formations were deposited under similar physiographic 
conditions. 

Lithologic character. — The Bone Valley gravel consists of a fine- 
grained matrix containing pebbles of phosphate or chert, fragments 
of bone, and other organic remains. The teeth and dermal plates 
of sharks and fish are so common in this formation that they may 
be gathered by the score from the washed material at the phosphate 
mines. The matrix is commonly sand, though a marly clay is not 
uncommon, especially in the lower part of the formation. The 
finer-grained material is soft and plastic when wet but hardens on 
exposure to the air. 

Partial sections of the Bone Valley gravel may b© observed in 
most of the land-pebble phosphate mines; these sections have cer- 
tain general characteristics which are worth noting. In some places 
a deposit of a few inches to several feet of light-gray to white sand 
or coarse sandy loam rests unconformably upon PHocene beds, which 
may be roughly divided into the nonproductive marls, gravels, and 
sand, and those which are commercially valuable on account of the 
high percentage of phosphatic pebbles they contain. The miners 
group the Pleistocene and the nonproductive Bone Valley gravel 
under the term ^^ overburden," because they must be removed in 
order to reach the productive beds. As the percentage of phosphate 
diminishes toward the top of the gravels, the organic remains become 
less numerous. This probably means that the deposition of the upper 
part of the gravels took place when the land was rising rapidly 
enough to rejuvenate the streams and thus permit them to carry 
materials from some distance inland. 

Thiclcness. — The Bone Valley gravel is exposed in the land-pebble 
phosphate mines, the excavations usually extending to the base of 
the formation and frequently reaching a depth of more than 30 feet 
before entering the underlying beds of the Alum Bluff formation; 



146 GEOLOGY AND GROUND WATERS OF FLORIDA. 

hence the thickness may be safely fixed at more than 30 feet. The 
average thickness, however, is probably lower and may not exceed 
15 to 20 feet. 

Physiographic expression. — The Bone Valley gravel occupies a region 
ranging from less than 100 to more than 150 feet above sea level, 
but the surface presents gentle slopes. The formation has been 
trenched by some of the larger streams which have eroded shallow 
valleys, and in places it forms low hills and ridges. Like some of 
the other Pliocene formations, the minor inequalities of the surface 
are locally masked by the younger Pleistocene beds. 

Paleontologic character. — The Bone. Valley gravel contaias abun- 
dant organic remains, such as fish and shark teeth and worn shfeUs. 
However, it is probable that some of these fossils were derived 
from the older geologic formations by erosion and by weathering. 
These are, therefore, to be regarded as contemporaneous with the 
phosphatic pebbles and older than the gravel in which they are found. 
The Bone Valley gravel, however, contains many fossils which are 
contemporaneous with the deposition of the beds, among them being 
teeth of horses, rhinoceroses, mammoths, sharks, and manatees. 

Structure. — Though the Bone Valley gravel shows no marked 
structural features it appears to have a gentle seaward inclination. 
From its mode of origin it is thought that this dip may be original 
and not the result of tilting subsequent to deposition. If the forma- 
tion has been folded the deformation is so slight that it does not show 
in the small exposures observable in the pebble-phosphate mines. 
However, it is not improbable that gentle arching, such as may be seen 
on Caloosahatchee River, also exists in the pebble-phosphate region. 

Areal distribution. — The Bone Valley gravel is widely distributed 
in the valleys of Peace and Alafia rivers, along which it is exposed 
in numerous phosphate mines. The exact extent of the formation 
is somewhat uncertain because natural exposures are rare and it is 
difficult to determine whether the beds are continuous beneath the 
covering of surface sand. Large areas of the Bone Valley gravel are 
known in De Soto, Polk, and Hillsborough counties, and smaller 
patches occur in some other counties. The largest areas are south 
and west of Bartow, where the formation is now being extensively 
exploited. 

PLIOCENE (?) SERIES. 

LAFAYETTE (?) FORMATION. 

Correlation. — Deposits referred to the Lafayette formation occupy 
large areas of the Coastal Plain and have been discussed by a number 
of authors, the most comprehensive report being that of McGee.* 
The name is derived from Lafayette County, Miss.,^ and is synony- 

» McGee, W J, The Lafayette formation: Twelfth Ann. Rept. U. S, Geol. Survey, pt. 1, 1891, pp. 347- 
621. 
2 Hilgard, E. W., Orange sand, Lagrange, and Appomattox: Ara, Geologist, vol. 8, 1891, pp. 129-131. 



GEOLOGY OF NOETHERN AND CENTRAL FLORIDA. 147 

mous with ^^ Orange sand " and ' 'Appomattox '' formation. However, 
it is apparent that each of these names has, at times, been used to 
include beds of different geologic ages, and hence the exact signifi- 
cance of the terms have varied with localities and even in a single 
locality, being used by different writers with different meanings. 
Berry ^ has recently shown that at the type locality near Oxford, 
Miss., the beds referred to the Lafayette formation belong to the 
Wilcox formation and are therefore of Eocene age. He states that 
at other places weathered deposits of Cretaceous age have been 
included in the Lafayette formation. 

Investigations made since the preparation of the manuscript for 
this report have shown that the beds referred herein to the Lafayette 
formation in Florida include sands and sandy clays belonging to 
the Alum Bluff and Choctawhatchee formations, together with 
similar materials of Pliocene age. The beds of Pliocene age are well 
developed in Florida, Alabama, and Mississippi but have not yet 
been given a specific name. As it is not possible at the present time 
to determine the correct ages of all the different exposures in Florida 
here referred to the Lafayette formation it was decided to retain the 
name in this report but with a query. 

StratigrapJiic position. — ^The deposits included in the Lafayette ( ?) 
formation have been observed to rest unconformably upon the Alum 
Bluff formation at Tallahassee. The amount of time represented by 
the unconformity is difficult to determine and it is probable that the 
erosion of the sands and clays and their redeposition on the slopes 
is recent. The surface on which the Lafayette (?) formation was de- 
posited appears to have been comparatively even; but this may mean 
either that the Alum Bluff had not been extensively eroded, or that 
it had been worn down to a nearly uniform altitude. In some places, 
the Lafayette (?) formation is unconformably overlain by the white 
sand of Pleistocene age, and in this case the extensive erosion of the 
Lafayette (?) indicates the lapse of considerable time, during which 
there were marked changes in the altitude and surface configuration 
of the land before the Pleistocene sands were deposited. 

LitTiologic character. — The materials composing the Lafayette (?) 
formation vary from clay and fine sand to coarse sand containing 
small pebbles, the whole being commonly stained with enough oxide 
of iron to give the deposit a deep-orange color. (See PI. XII, A.) 
The variation in physical character, together with the lenticular 
shape of many of the beds and numerous instances of cross bedding, 
show the changing conditions under which the beds were deposited. 
Under such conditions numerous unconformities are to be expected, 
but it is seldom possible to determine their extent because the expo- 
sures are poor. 

1 Berry, E. W., The age of the type exposures of the Lafayette formation: Jour. Geology, vol, 19, No. 3, 
AprU, May, 1911, pp. 249-256. 



148 GEOLOGY AND GROUND WATERS OF FLORIDA. 

Thickness. — Though widely distributed, the Lafayette ( ?) formation 
is comparatively thin, seldom exceeding 30 to 60 feet, and having 
perhaps an average thickness of less than 50 feet. 

PJiysiograpJiic expression. — The Lafayette ( ?) formation has under- 
gone extensive erosion since its deposition, and so much of the original 
material has been reworked and redeposited under different condi- 
tions and in different physiographic positions that it is now difficult to 
determine which deposits were original and which are to be classed as 
the secondary products from the erosion of the original. However, con- 
siderations of physiography suggest that the more or less fiat-topped 
hills and dissected table-lands in the northern part of the State can 
best be explained as remnants of a more extensive plain formed when 
the region was one of low relief. It is difficult to make any close 
correlation between the separate remnants of this upland because 
the amount of erosion has varied greatly. The general range in 
altitude is approximately 50 feet, and there is a gradual increase 
from about 250 feet above sea level at the southern margin of the 
upland to nearly 300 feet along the northern boundary of the State. 

Paleontologic character. — The deposits referred to the Lafayette ( ?) 
formation are not known to contain fossils of marine organisms 
except such as have been derived from the erosion of older strata. 
Remains of land and fresh-water fossils have been found outside the 
State; but no fossils of any sort have been reported from the beds 
tentatively assigned to this formation in Florida, and since the beds 
are well exposed it appears safe to say that they do not contain 
many fossils. 

Structure. — The Lafayette (?) formation shows no structural 
features of interest, though it may have been subjected to the same 
deformation which produced the gentle arching of the marine Plio- 
cene beds. 

Areal distribution. — The deposits referred to the Lafayette ( ?) for- 
mation occupy a belt about 40 miles wide, extending from near Suwan- 
nee River westward to Escambia County. Large tracts are found 
in Gadsden, Leon, and Jefferson counties on the east side of Apalachi- 
cola River; and in Holmes, Walton, Santa Rosa and Escambia coun- 
ties in west Florida. They are best developed in the uplands of 
the counties along the north line of the State, but show few good 
exposures. The red sands of the counties mentioned are largely 
assigned to the Lafayette (?) formation, but their age is doubtful 
because of the absence of fossils. The selection of typical sections 
of the Lafayette ( ?) formation is a difficult task because of the uncer- 
tainty which frequently attends the identification and correlation of 
exposures. The sections given below are few, but they are fairly 
representative of the materials included in the Lafayette ( ?) formation 
in Florida. Sands belonging to this formation have already been 
mentioned in connection with the sections of other formations. 



U. S. GEOLOGICAL SURVEY 



WATER-SUPPLY PAPER 319 PLATE XII 





A v-- '< 




f V; ''^>*'**^%_ ji!?^ 


1 »'^ '' JHp^BM^^BI 


^jiig^^XjC|«.- .^a 







^. CONGLOMERATE OF LAFAYETTE (?) FORMATION, RESTING ON SANDSTONE OF 
UNCERTAIN AGE, TOP OF ROCK HILL, WASHINGTON COUNTY. 




B. ROCK FACE IN COQUINA QUARRY, ANASTASIA ISLAND. 



GEOLOGY OF NOETHERN AND CEKTRAL FLORIDA. 149 

In the descriptions of sections, made by Vaughan in the vicinity 
of Tallahassee, the red sands are assigned to the Lafayette ( ?) forma- 
tion, though they are probably weathered portions of Oligocene 
beds. 

Section on St. Augustine road from HancocFs place to the Seaboard Air Line Railway, 

south side of railway. 
Lafayette (?): Feet. 

Clay, red, sandy (from plateau summit) 55 

Alum Bluff: 

Clay, gray, interlaminated with sands; and gray clays (level 
of railroad) 16 

In this section the contact of the sands and clays shelves downward 
toward the north, descending through 16 feet. The contact dips at 
a less angle than the clay for a stretch of 20 feet. 

In ravines near the southern edge of Tallahassee several small 
exposures show the red sands of the Lafayette ( ?) formation resting 
on older sands and clays. The red sands mantle the slope and the 
total thickness of the section is about 55 feet. At the base of the hill 
there is an exposure of gritty sand; 5 feet above the base of the sec- 
tion there is a bed of gray clay; and 15 feet higher there is an exposure 
of gray grit. The clay at the base of this bluff is probably 20 feet 
above the clay iq the section above. 
Section on Bellair road, south from Tallahassee, south side Seaboard Air Line Railway. 

Pleistocene : Feet. 

Soil, sand, etc 1 

Alum Bluff: 

Clay, massive, plastic, gray blue; cuboidal fracture 10 

Sands, and siliceous clay (of the appearance of Alum Bluff). . . 3+ 

By aneroid the base of this section is 60 feet below the capital 
terrace and 30 feet above the railroad crossing. 

Vaughan's comment is that ''the clays at this locahty are lower 
than in Tallahassee and higher than on the St. Augustiae road; 
that is, the contact between the red sands and the underlying clays 
is an uneven surface. The actual relations between the sands and 
clays were difficult to observe, but the indications from aneroid 
observations are that the sand rests on an uneven, probably eroded 
surface." 

Section at McCulloughs Bridge, 10\ miles northwest of De Funiah Springs,^ just below 

mill pond. 

Feet. 

Sands, light yellowish gray. . ., 3 

Sands, red, gritty and small pebbles, somewhat argillaceous, with 

clay seam, ^ to 2 inches thick, cross-bedded on a large scale near 

the base 10± 

Unconformity. 

Sands, yellow, argillaceous, interlaminated with gray clay 6^ 

Lafayette (?) formation. 

1 Vaughan, T. W., unpublished notes. 



150 GEOLOGY AND GROUND WATERS OF FLORIDA. 

A local resident says that this outcrop is on sec. 2, T. 4 N., R. 20 W. 

In an exposure on Eock Hill south of Chipley the upper member 
probably represents the Lafayette (?) formation. The age of the 
lower part could not be determined. The section follows: 

Section on Rock Hill south of Chipley. 

Feet. 
Sand, red, and gravel, containing pebbles up to 1 inch. In places 

cemented into hard conglomeratic bowlders several feet through... 20 
Sandstone, hard, yellowish gray to green, with pebbles of soft green 
clay 10 

Sections of the Lafayette ( ?) were observed on the tops of hills about 
250 feet above tide on the road between E-iver Junction and Aspalaga 
Bluff. A short distance from River Junction the following section 
was leveled : 

Section near River Junction. 

Feet. 

Sand, red, containing numerous pebbles 8-10 

Sand, red, argillaceous. 45 

Clay, gray, marly, stained with iron oxide 1+ 

About 5 miles from River Junction a similar exposure was observed. 

Section 5 miles from River Junction. 

Feet. 
Sandstone, friable, orange; containing some lenses of clay and some 
pebbles 15 

Sandstone, gray; streaked with yellow iron stains; well cemented. . 5 

QUATERNARY SYSTEM. 
SUBDIVISIONS. 

The Quaternary is commonly divided into Pleistocene and Recent, 
but a difficulty often arises in attempting to discriminate these 
subdivisions, for the reason that the name Pleistocene is associated 
with the glacial epoch and Recent with the time since the final 
melting of the great sheets of ice which covered large areas in the 
north of Europe and North America. In regions like Florida^ remote 
from the direct influence of glaciation, it is everywhere difficult and 
in many places impossible to draw satisfactory lines between the 
deposits of the two epochs. In the following discussion Quaternary 
will be applied to deposits which may belong to either Pleistocene 
or Recent or both, and Pleistocene will, so far as possible, be restricted 
to such beds as may safely be placed in the early part of the Qua- 
ternary and are probably to be correlated chronologically with the 
glacial deposits farther north. Recent will be restricted to deposits 
such as sand dunes and alluvial sands which are clearly of late geo- 
logic age. In general it is considered safe to draw the line between 



GEOLOGY OF NOBTHERN AND CENTRAL FLORIDA. 151 

the two epochs at the final emergence of the lowlands from beneath the 
sea; and, as this movement appears to be the most marked physical 
change since the early Quaternary, it probably forms the best line 
of demarcation between Pleistocene and Recent. Theoretically the 
line may be drawn with considerable exactness, but practically the 
discrimination of Pleistocene and Recent deposits often presents 
many difficulties because the changes in conditions governing depo- 
sition were gradual and the materials for the Recent deposits were 
often derived directly from the beds of late Pleistocene age. 

PLEISTOCENE SERIES. 

SUBDIVISIONS. 

In Florida beds of Pleistocene age include both md^rine and non- 
marine deposits, and the nonmarine beds may be separated, on the 
basis of origin, into residual, lacustrine, fluviatile, and eolian. On 
a basis of character the Pleistocene deposits may be described as 
fossiliferous marls, gray sand, ^^Planorbis rock," coquina, ^'Vermetus 
rock," and yellow clay. 

Fossiliferous marls. — The fossiliferous marine Pleistocene is one of 
the most interesting of the Quaternary formations. It comprises 
sands and shell marls in a sandy matrix. On North Creek, a tribu- 
tary of Little Sarasota Bay, Dall ^ obtained a large number of fossils 
from a shell bed consisting of sand darkened by organic matter and 
having a total thickness of less than 2 feet. 

During the field work for this report collections were obtained 
which indicate that the fossiliferous Pleistocene is much more ex- 
tensively developed than was formerly believed. The beds contain- 
ing fossils of this age present great uniformity in character, being 
composed of white or light-gray sands, commonly coarse grained and 
in some places containing layers of marine or fresh-water shells. A 
few beds of clay occur interstratified with the sand, and in a few 
localities the sand contains scattered argillaceous material. Most 
of the fossils are found near the base of the beds and the fauna in 
some places changes from marine near the bottom of the exposure 
to nonmarine above, indicating a freshening of the water during 
deposition. In many localities the fossils are confined to the lower 
layers of sarid; and, in such places, the absence of fossils in the upper 
part of the sand may have been caused by the partial emergence of 
the beds during deposition. Sharks' teeth, pieces of bone, and other 
organic remains are found in the basal portion of these sands at some 
places, probably eroded from the underlying formations. An un- 
common but interesting example of such a conglomerate, foui^d by 

1 Dall, W. H., Trans. Wagner Free Inst. Sci., vol. 3, pt. 6, 1903, pp. 1615-1616. 



152 GEOLOGY AKD GEOUND WATEKS OF FLORIDA. 

Stephenson at Stokes Ferry on St. Marys River, comprises a shark's 
tooth, a fragment of a mammoth's tooth, the ear bone of a whale, a 
fragment of a plate from the shell of a turtle, three horse's teeth, and 
indeterminate bone fragments. Pebble phosphates occur m the lower 
layers of the sands of Pleistocene age. Some unsuccessful attempts 
have been made to mine them, but the deposits have usually been 
found too thin to be of economic value. Phosphates of this character 
are to be found at many localities in the peninsula. They represent 
the hard materials separated from the residual clays and sands by 
the action of the waves and currents in the Pleistocene sea. The 
absence of extensive clay beds in the sands of Pleistocene age is due 
to its scarcity in the older geologic formations from which the sands 
were derived. This characteristic of the rocks of Florida is so pro- 
nounced that good clays are comparatively rare, except in certain 
localities of limited area. 

Fossilif erous marine beds of Pleistocene age are probably more widely 
distributed in Florida than in any other State east of the Appalachian 
Mountains. Pleistocene fossils were collected from the marls at 
Labelle, Sarasota Bay, Manatee River, and Sixmile Creek (near 
Tampa), on the west coast, and at Fort Lauderdale, Eau Gallic, 
Titusville, Daytona, and Mims on the east coast. In the center of the 
peninsula no exposures of marls were noted, but samples obtained at 
a depth of 100 feet in the well of H. Clay Johnson, at Kissimmee, 
show that the marine marls of Pleistocene age occur at that locality 
beneath nearly 100 feet of sand. This suggests that they probably 
extend some distance north of Kissimmee in the east-central portion 
of the peninsula. The distribution of the exposures of the marls over 
so wide an area in a region where the beds are practically horizontal 
and undisturbed, as is the case in the southern part of the peninsula, 
indicates that the marls probably underlie a very large area. Thus 
they doubtless extend along the western coast from Tampa south- 
ward to near Fort Myers. From a point near Labelle the inner 
margin swings northward, passing east of Arcadia and Bartow to 
some distance north of Kissimmee, and then turns eastward. On 
the east side of the peninsula the marls of Pleistocene age extend north 
to Orange City and Mims, and they probably extend through the low 
valley occupied by St. Johns River. Throughout the area where 
these beds are known, they maintain striking similarity of texture 
indicating widespread uniformity in the conditions governing their 
deposition. 

In general the Quaternary formations in the northern part of the 
State and as far south as Lake Okechobee present small differences ; 
hence the discussion of local details is omitted except in the case of 
the shell marls. A section of the Pleistocene shell marl at Orient 



GEOLOGY OF KORTHEKN AKD CENTRAL FLORIDA. 158 

station, where it rests unconformably on the Tampa formation, 
follows : 

Section at Orient station. 

Feet. 

Sand, white 2 

Marl, white, sandy 6 

Sand, light gray 1 

Shell marl, gray 0-1 

The lower member of the above section furnished many species of 
fossils identified by Vaughan as Pleistocene. 

In a ditch about one-eightli mile south of Manatee station, an 
exposure of sandy marl contains an abundance of Pleistocene fossils. 
One-fourth mile south of the railroad station at Orange City an 
exposure of marl is doubtfully referred to the Pleistocene, though 
further fossil collections may show it to be Pliocene. The section at 
this last locality has a thickness of about 18 feet, but only the lower 
part is f ossilif erous : 

Section one-fourth mile south of Orange City station. 

Feet. 

Sand, unassorted, white 3 

Clay, stratified, hard, white, sandy. .• 3 

Sand, well stratified, ferruginous, and clay 5 

Marl, yellow to white, very fossilif erous 7 

18 

From a well at Kissimmee Vaughan obtained fossils which he 
regarded as Pleistocene. It is interesting to note that the sample 
came from about the same depth as those mentioned in discussing the 
Pliocene (p. 141). 

A loosely cemented sandy shell marl a mile west of Titusville fur- 
nished several shells identified as Pleistocene, and many worn frag- 
ments. In a ditch 4 miles west of Eau Gallic a good exposure of 
sandy shell marl covered by from 1 to 3 feet of white Pleistocene sand 
yields Pleistocene fossils. Two miles southeast of Eau Gallie, on 
Merritts Island, a section shows about 8 feet of coquina covered by 
2 to 4 feet of white Pleistocene sand; the lower part of the sand sup- 
plied several species of Pleistocene fossils, and there is no doubt that 
the coquina, though slightly older, belongs to the same epoch as the 
overlying sand. 

Well records in many parts of the State show Pleistocene beds, but 
only where samples have been preserved has it been possible to 
recognize with certainty the shell marls of that age. In the well 
at Ormond Hotel, Ormond, in a sample of hard sandy marl from a 
depth of 50 to 56 feet Vaughan identified Donax variabilis Say, etc. 
A gray sandy marl, lying between 66 and 68 feet, furnished Littorina 



154 GEOLOGY AKD GEOUND WATEES OF FLOEIDA. 

irrorata Say, Area pexata Say, and Mulinia lateralis Say. Vaughan 
regarded these samples as Pleistocene. At a depth of 66 to 90 feet 
the material was still a marl, but unfortunately the organic remains 
were too meager to show whether the material was Pleistocene or 
Pliocene. 

The well of the Model Land & Railroad Co., at West Palm Beach, 
may be entirely in the Pleistocene, but fossils were identified (by 
Vaughan) only from samples 4 and 5. Sample 4, from 55 to 70 feet, 
furnished Crepidula fornicata Say, Pecten gihhus Linn., Cardium 
rohustum Sol., and Venus mortoni Conrad, which were thought to be 
Pleistocene; and this conclusion was strengthened by the occurrence 
of Donax variabilis Say in sample No. 5, which was obtained at 70 to 
74 feet. In another well at the same locality the Pleistocene marls 
were identified in samples extending from 8 to 57 feet. 

Gray sand. — One of the most widespread deposits of the Atlantic 
and Gulf Coastal Plain is a white or light-gray coarse-grained sand. 
Locally some of the subsurface layers of this sand have been stained 
light yellow or even red by a deposit of iron oxide, but the colors when 
present are usually less prominent than those of the Lafayette forma- 
tion. This material, which has commonly been called white sand, 
covers nearly all of Florida below the 100-foot contour, and rests 
unconformably upon the older geologic formations. (See PI. V.) It 
forms the surface over all the lowlands and extends upon the sea- 
ward margin of the elevated region toward the north end of the State. 
In the valleys, the white sand forms a mantle over a large part of the 
slopes, where it is arranged in more or less well-defined terraces. 
Locally this sand has been removed from hillsides by erosion. 

Lithologically this sand presents no marked peculiarities. It is 
everywhere coarse and is on the whole remarkably free from silt or 
clay. The sand grains are not materially different in form from 
those of the present beach and belong to the type commonly known 
as '^ sharp" sand, being subangular to subrotund. In this they differ 
from sands which have undergone extensive wind transportation and 
have been well rounded by violent impact with other sand grains 
when not buoyed up by liquid. Clay beds are generally absent, and 
the sands are apparently nonfossiliferous except near the base of the 
sections, which extend down nearly to or below sea level. 

The gray sands are usually uncemented, but locally the presence of 
iron oxide has transformed them to a concretionary sandstone. A 
driller reported a pine log embedded in incoherent sands, probably of 
Pleistocene age, at a depth of 60 feet in a well at Carrabelle. Other 
examples of vegetable matter as well as logs, noted at numerous 
localities in Florida, suggest that swamps may have existed during 
the deposition of the sands, but the absence of any considerable 
bodies of peat interbedded with the sand shows that such marsh 



U, S. GEOLOGICAL SURVEY 



WATER-SUPPLY PAPER 319 PLATE XIII 




A. COQUINA ROCK ON GULF SIDE OF SARASOTA KEY. 




B. TURTLE MOUND, AN ANCIENT SHELL MOUND ON NORTH INDIAN RIVER. 



GEOLOGY OF NORTHEKN AND CENTRAL FLORIDA. 155 

conditions must have been of short duration or that the supply of 
sediment was sufficient to prevent the accumulation of thick layers of 
pure organic matter. 

The thickness of the gray sands is seldom sufficiently great to mask 
the major features of the topography of the underlying formations 
except where there are well-defined terraces. 

"Planorhis marV^ — After the deposition of the main body of the 
gray sands, a number of shallow bodies of fresh water appear to have 
occupied depressions in the surface of the newly emerged land. In 
these bodies of fresh water there accumulated thin deposits of marl 
which differ from the earlier marls of the epoch in being composed of 
calcareous matter nearly free from sand. In this marl the most 
conspicuous fossils are gastropods, especially those belonging to the 
genus Planorbis. This rock may be in part post-Pleistocene but can 
not be satisfactorily subdivided at the present time. It should not 
be confounded with the ''Planorbis rock" of Caloosahatchee River, 
which has been regarded as Pliocene. ''Planorbis marl" of Quater- 
nary age has been observed at Daytona, Sanford, and on Santa Fe 
River southwest of Fort White; and, according to Eldridge,^ it occurs 
in most of the "hammocks" between Kissimmee and Lake 
Okechobee. 

The Quaternary deposits of the southern end of the peninsula and 
the keys will be discussed by Mr. Sanford. (See pp. 174-199.) 

Goquina. — One of the most common of the marine Quaternary 
deposits is coquina, a mass of more or less waterworn shells loosely 
cemented by calcium carbonate, which occurs in numerous places 
along the coast. The amount of cement is seldom great enough to 
close the openings between the individual shells, though in some 
localities the process of cementation has proceeded far enough to 
produce a rather compact fossiliferous limestone. More or less sand 
is commonly included in the form of thin laminae separating the shell 
beds, and gradations from sandrock to shell rock may be noted. (See 
Pis. XII, B (p. 148), and XIII, A.) 

This rock was described by several of the earlier writers on the 
geology of the State. The following account is from a paper 
published by Pierce in 1825.^ 

Extensive beds of shell rock, of a. peculiar character, occupy the borders of the 
ocean in various places from the river St. Johns to Cape Florida. They are composed 
of unmineralized marine shells of species common to our coast, mostly small bivalves, 
whole and in minute division, connected by calcareous cement. I examined this 
rock on the isle of Anastasia opposite St. Augustine, where it extends for miles, rising 
20 feet above the sea and of unknown depth. It has been penetrated about 30 feet. 
In these quarries horizontal strata of shell rock of sufficient thickness and solidity for 
good building stone alternate with narrow parallel beds of larger and mostly unbroken 

1 Eldridge, G. H., unpublished notes. 

2 Pierce, James, Am. Jour, Sci., 1st ser,, vol. 9, 1825, p. 123. 



156 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

shells, but slightly connected. Hatchets are used in squaring the stone. Lime is 
made from this material, of a quality inferior to ordinary stone lime. 

The large Spanish fort [Fort Marion] and most of the public and private buildings of 
St. Augustine are constructed of this stone. The rock extends in places into the sea, 
with superincumbent beds of new shells of the same character. 

Similar shell rock is found on the continent in several places. 

'.' Vermetus roclc.'' — Another organic rock, which has been de- 
scribed by Dall/ is now being formed by colonies of a small gas- 
tropod, Vermetus (PetaloconcJius) nigricans. This organism secretes 
a skeleton in the form of a winding calcareous tube, and when the 
tubes of a colony are seen united together they are thought to resem- 
ble coral, hence the local name ^^worm coral." This rock is now 
being formed on the coast, and it doubtless extends back to the 
Pleistocene and possibly even to the Pliocene, for Dall ^ reports the 
same species of gastropod from the Caloosahatchee marl. 

Of the organic Quaternary rocks Dall says: ^ 

There is a general opinion among the inhabitants, which was frequently expressed 
to me in conversation, to the effect that between Tampa and the Keys coquina rock 
is only to be found at one place, the mouth of Little Sarasota Pass. But this idea is 
certainly erroneous, as at every projecting point of the keys along the Gulf shore 
which we visited I found traces of this rock, though often not visible above water 
and frequently composed more of sand grains than of shell, so that it looks much like 
wet loaf sugar. 

Yellow clay. — With the Pleistocene is included a silty or sandy 
yellow clay which is found in some places on the highlands in the cen- 
tral part of the peninsula. This material, which is evidently the 
residual product left by the decomposition of the underlying rock, is 
found on all the Oligocene formations and it doubtless began accu- 
mulating immediately after the final emergence of these beds from 
beneath the sea. However, much of it has doubtless been removed, 
and what remains represents in the main the results of weathering since 
the depression which resulted in the deposition of the marine PHocene 
beds, though probably part was formed during preceding epochs. 
For convenience it is all included under Pleistocene. It was this 
material which Dall^ described as yellow sand; from the analysis 
which he gives, it appears to be about 80 per cent silica. Lime, 
locally an important constituent of the original rock, has dwindled 
to less than 2 per cent, but this condition is to be expected, as the 
residuum of the weathering of limestone is tjie insoluble silica and 
sihcates which existed as impurities in the original rock. 

STRATIGRAPHIC POSITION OF THE PLEISTOCENE. 

Where observed, the contact between the gray sands of Pleistocene 
age and the older formations is characterized by marked unconform- 

1 Bull. U. S. Geol. Survey No. 84, 1892, p. 153. 

2 Geology of Florida: Am. Jour. Sci., 3d ser., vol. 34, 1887, pp. IQZ-19S. 

3 Bull. U. S. Geol. Survey No. 84, 1892, pp. 154-156. 



GEOLOGY OF NORTHEEN AND CENTRAL FLORIDA. 157 

ity due to erosion. The contact between the gray and yellow sands 
has been observed at many locahties and is one of unconformity. 
The yellow sand appears to pass by gradation into the underlying 
Tertiary from which it was derived by weathering. The strati- 
graphic relations between the coquina, the ^'Vermetus rock/' and 
the underlying beds have not been observed but they doubtless show 
unconformity. 

With the exception of the yellow residual sand the several mem- 
bers of the Pleistocene and the overlying Recent deposits exhibit 
conformable relations. In fact the gradation between Pleistocene 
and Recent beds often makes it impossible to differentiate them. 
This is the case with the sands of Recent age, which are usually 
derived from the erosion and redeposition of the sands from the beds 
of Pleistocene age. Much of the material has not been transported 
far, and in many deposits the lack of definite arrangement of the 
layers renders the recognition of unconformity very uncertain. The 
interpretation of the observations is also subject to considerable 
unreliability because it is difficult to say whether such unconformities 
as are seen are general or merely local. 

THICKNESS OF THE PLEISTOCENE. 

In Florida the beds of Quaternary age vary greatly in thickness, 
and in some localities they are wholly wanting. The differences in 
thickness are due to uneven deposition on a surface which had been 
more or less dissected by erosion. The gray sands are commonly 
not more than 20 or 25 feet thick, but in places they rise in sand 
dunes 40 to 50 feet high, and hence their maximum thickness is over 
50 feet. 

The thickness of the coquina is difficult to determine, because 
sections showing the base are wanting and many well records are 
unreHable, the driller often reporting as ''coquina'' any soft rock 
that contains abundant sheU fragments. However, at St. Augustine 
it is known to attain a thickness of over 30 feet, and at many points 
along the east coast it outcrops with a thickness of 10 or 12 feet. 

Few exposures of the shell marls are more than 3 to 4 feet thick, 
unless the unfossiliferous gray sand immediately overlying them is 
included, when these figures will usually be increased three to four 
fold. The data supplied by well samples show that the Quaternary 
along the east coast varies in thickness from about 40 feet at Jack- 
sonville to over 70 feet at West Palm Beach and more than 100 feet 
at Miami. 

Concerning the deposits along the west coast the information is 
much less satisfactory, and it is probable that from Manatee River 
northward nearly to Carrabelle the thickness of the Quaternary 
deposits averages less than 30 feet, though in places it exceeds 50 
feet. In a well at Carrabere the ^'Sopchoppy limestone" was en- 



158 GEOLOGY AND GROUND WATERS OF FLORIDA. 

countered at about 50 feet, but some of the overlying sands and clays 
may be older than the Quaternary. Westward, in the vicinity of 
Pensacola, there is a great thickness of sands with some thin clay beds. 
Satisfactory collections of fossils from these sands have not been 
obtained, but it appears probable that the Quaternary may attain 
a thickness of several hundred feet near the coast. At Kissimmee, 
in the south-central part of the peninsula, the presence of Pleistocene 
fossils in a well at a depth of 100 feet indicates that the beds thicken 
toward the south. 

On the uplands of the peninsula the yellow sandy clay has been 
penetrated for over 50 feet in the vicinity of Lakeland, and at other 
localities in the south-central part of the peniosula it is known to 
have a thickness of 20 to 30 feet. 

PHYSIOGRAPHIC EXPRESSION OP THE PLEISTOCENE. 

In the coastal belt the Quaternary is characterized by low relief, 
forming a region of low sandy plains crossed by shallow valleys and 
containing many broad marshes and ponds which are seldom more 
than 2 to 3 feet in depth. The Quaternary of the interior for the 
most part exhibits the same topography as the underlying rocks, 
except where it is sufficiently thick to form well-defined terraces. In 
some localities, especially along the east coast, wind action has buUt 
the sand into dunes and ridges, which in some places rise to 30 to 50 or 
more feet and form conspicuous topographic features. 

PALEONTOLOGIC CHARACTER OF THE PLEISTOCENE. 

That the Pleistocene fauna bears a close resemblance to that now 
living along the coast is illustrated by the collection of fossils from 
North Creek which, according to Dall,^ comprised 71 species, of which 
5 are believed to be extinct.^ 

STRUCTURE OP THE PLEISTOCENE. 

The beds of Pleistocene age show no indications of having been 
subjected to marked deformation, and their general attitude has 
probably not been materially changed since their deposition. They 
seem to have a gentle dip toward the sea and they were apparently 
raised to their present altitude by a broad movement which was not 
of such a character as to produce notable flexures. 

RECENT SERIES. 

The Kecent formations of Florida include alluvial and lacustrine 
deposits, Eecent beach sand and sandrock, coquina, oyster reefs, coral 
reefs, and eolian sand. 

1 Trans, Wagner Free Inst. Soi., vol. 3, pt. 6, 1903, p. 1616, 

2 For lists of fossils, see Matson, G. C, and Clapp, F. G., A preliminary report of the geology of Florida 
with special reference to the stratigraphy: Second Ann, Rept. Florida Geol. Survey, 1909. 



GEOLOGY OF NORTHERN AND CENTRAL FLORIDA. 159 

ALLUVIAL DEPOSITS. 

The alluvial deposits occur along all large streams in belts from a 
few yards to a mile or more in width. They are divisible into Recent 
flood-plain deposits and terrace deposits of Pleistocene age. During 
high water the flood plains are partly overflowed; and in some locali- 
ties the inundated tracts take the form of nearly impenetrable cypress 
swamps which are partly flooded during a large part of the year. 

The Recent silts and sands in few places rise more than a few feet 
above the high-water levels of the streams, and the transition to the 
terraces above is generally poorly defined. The terraces were formed 
during a submergence in the Pleistocene epoch. Both flood plains 
and terraces are composed of coarse white sand, or, locally, of yellow 
and red sands derived from the erosion of the Lafayette ( ?) formation. 
Silt and clay are comparatively rare, though a few of the smaller 
swamps are underlain by these materials. Shells of land and fresh- 
water mollusks occur in the flood-plain deposits, but few of them are 
of importance. The fluviatile deposits of this age often contain more 
or less gravel, with phosphatic pebbles derived from the erosion of the 
Bone Valley gravel and other phosphate-bearing formations. This 
material was formerly dredged from the beds of the streams and was 
known as river-pebble phosphate. 

LACUSTRINE DEPOSITS. 

The deposits here classed as lacustrine include those now bemg 
formed in the numerous lakes and swamps. They consist of gray 
sand derived from beds of Pleistocene age, and animal and vegetable 
remains supplied by the growth and decay of aquatic organisms. 
The sand does not differ greatly from the white sand of Pleistocene 
age which covers such a large part of the surface of the State. Where 
the organic deposits consist of molluskan rem^ains mixed with sand 
they form shell marls and where -animal remains predominate they 
form beds of soft marly limestone. On the bank of St. Johns River, 
at the mouth of Blue Spring Outlet in Volusia County, a semicrystal- 
line limestone more than 4 feet thick, overlain by 3 feet of sand, con- 
tains many shells of a fresh-water mollusk (Unio) ; and the overlying 
sands contain shells of the common land snail {Helix albolabris). 
From the position of these beds the sand is evidently of Recent age 
and the limestone may belong to the Pleistocene. 

The vegetable remains form beds of peat or muck, few of which, 
outside of the Everglades, attain a thickness of more than a few feet 
and many of which are to be measured in inches. Locally they con- 
tain thin beds of sand which were evidently washed into the swamp 
and in many places considerable organic silica in the form of tests of 
diatoms. These deposits, which are known as diatomaceous or in- 
fusorial earth,' are sometimes mined and sold for silver polish. Such a 
mine was formerly operated near Eustis. 
76854°— wsp 319—13 11 



160 GEOLOGY AND GKOUND WATEES OF FLOKIDA. 

"VERMETUS ROCK." 

Under the head of Pleistocene mention was made of the '^ Vermetus 
rock" formed of the tube-shaped calcareous skeletons of a gastropod. 
Although the formation of this rock probably began in the Pleistocene 
or even earlier, its accumulation has continued down to the present 
time and it forms one of the most interesting of the Kecent deposits. 

OYSTER REEFS. 

At the mouths of many of the rivers and at many points in the 
sounds that border the Florida coast oyster beds are numerous. The 
shells accumulate in large numbers and become cemented into hard 
jagged rock that is locally a menace to small boats. Oyster beds and 
the rock formed by their cementation may be found in most of the 
so-called rivers along the east coast, where they clog what is known 
as the Iiiside passage; they may also be found obstructing the mouths 
of rivers behind the offshore bars. Such reefs are not confined to 
the east coast, for they may also be found along the west side of the 
peninsula and along portions of the coast of west Florida. Their 
growth is so rapid that frequent local dredging is necessary in order 
to keep shallow channels open for navigation. 

CORAL REEFS. 

The coral reefs are restricted to southern Florida, and as they have 
been fully discussed by Mr. Sanford (see pp. 197-198) no description 
of them need be given here. 

BEACH DEPOSITS. 

The Recent beach deposits consist largely of sand, though a friable 
sandrock is not uncomm-on: and the formation of coquina, which 
began as early as the Pleistocene, has continued down to the present 
time. The gray sand derived from the Pleistocene deposits is by 
far the most common material, though locally fragments of rock 
derived from some of the older geologic formations predominate. 
Such rock has been noted by Heilprin ^ on Chassahowitzka River, 
and by Dall ^ at several points along the west coast south of Tampa. 
An admixture of recent and extinct fossils may result from the 
erosion and redeposition of the older formations. 

EOLIAN DEPOSITS, 

The eolian deposits consist of sand in the form of dunes, ridges, 
or more or less irregular hillocks, which occur in many localities from 
the northern line of the State southward to the vicinity of Lake 
Okechobee, but which are best developed along the east coast. In the 

1 Explorations on the west coast of Florida: Trans. Wagner Free Inst. Sci., vol. 1, 1887, pp. 57-58. 

2 Bull. U, S. Geol. Survey No. 84, 1892, p. 153. 



GEOLOGY OF NORTHERN AND CENTRAL FLORIDA. 161 

interior few ridges or dunes are conspicuous, this probably being 
ascribable to the vegetation and climatic conditions. During a large 
part of the year the ground water stands very near the surface, espe- 
cially where the relief is slight, and serves to keep the sand moist and 
prevent its being blown about by the wind. 

Another factor which hinders the formation of dunes in the interior 
is the general absence of strong winds blowing from a single direction. 
This is well shown by contrast with the islands along the east coast, 
where the prevailing winds from the northeast have resulted in the 
formation of dunes, some of which attain a height of over 50 feet 
as far south as Dade County. And, finally, the presence of luxuriant 
subtropical vegetation not only protects the sand from the direct 
force of the wind but also tends to hold it in place by a matting of 
roots and stems. 

CHEMICAL DEPOSITS. 

In a region where solution is so extensive chemical deposits would 
naturally be expected, but except at the extreme southern end of the 
State such deposits do not appear to be important. The chemical 
deposits are of two classes, one being dropped from underground 
water, where it emerges in the form of springs, and the other being 
deposited in crevices and caverns beneath the surface. The spring 
deposits vary with the character of the material in solution. The 
waters containing hydrogen sulphide deposit sulphur, which appears 
as a white flocculent material coating the plants and earth at the 
point of emergence. Other waters deposit carbonate of lime or 
hydrated iron oxide (limonite). Examples of the deposition of sul- 
phur may be found at any sulphur spring or weU, but lime and iron 
deposits are much less common. The subject of deposition in crev- 
ices and caverns has already been considered in the discussion of 
cavern formation (p. 26). In the first annual report^ of the Geologi- 
cal Survey of Florida mention was made of the occurrence of sulphur 
near Floral City, and it was suggested that the deposit m.ay have been 
the result of the decomposition of hydrogen sulphide gas escaping 
from underground waters. 

Recent investigations by Drew ^ have shown that the chemical 
formation of limestones is much more rapid than has generally been 
supposed, and Vaughan ^ has discussed the formation of calcareous 
sediments in Florida in considerable detail. The most important 
chemical deposits now being made are the layers of calcium carbonate 
precipitated by the action of denitrifying bacteria in shallow seas. 
This precipitation accounts for the large amount of calcareous ooze 

1 Sellards, E. H., First Ann. Rept. Florida Geol. Survey, 1908, pp. 44-45. 

2 Year Book Carnegie Inst. Washington No. 11, 1912, pp. 136-144. 

* A contribution to the geologic history of the Floridian Plateau, Pub. Carnegie Inst. Washington No, 
133, 1910, pp. 135-138. 



162 GEOLOGY AND GKOUND WATERS OF FLORIDA. 

found in the Bay of Florida and adjacent to the living coral reef. 
Vaughan^ has recently shown that oolites are now being formed 
from the ooze in the neighborhood of the keys and in shoal water near 
the Bahamas. 

The investigations of Drew and Vaughan, cited above, have deter- 
mined how chemical deposits are made and have shown how important 
a role some hitherto unknown agencies may play in the formation of 
limestones and oolites. 

A detailed discussion of the limestones and oolites of southern 
Florida, where chemical deposition is most active, has already been 
given by Mr. Sanford (pp. 175-191), and it is therefore unnecessary 
to describe them here. 

HUMAN REMAINS. 

For many years Florida has been a very important collecting 
ground for human relics. Both sand and shell mounds are common 
along the coast, and sand mounds occur at many localities on the 
banks of the principal streams farther inland. Some of the sand 
mounds appear to have been used for dwelling places and others to 
have served as burial grounds. Several accounts have been pub- 
lished,^ describing the skeletons, implements, and pottery obtained 
by excavating in these mounds. Apparently all the mounds are built 
of Pleistocene sands or shells of living moUusks, and they are doubt- 
less of Recent geologic age. (See PI. XIII, B, p. 154.) 

In 1871 attention was drav/n to a skeleton found by J. G. Webb 
near Osprey, Manatee County. Subsequently, other human remains 
were discovered in the same county,^ on the farms of J. G. Webb and 
of J. W. Webb, both near Osprey; at Hanson Landing, 8 miles north 
of Osprey, and 1| miles south of Osprey. 

Chemical analysis showed that the bones had undergone consider- 
able change, especially in the diminution in the phosphates and other 
compounds of lime, and a corresponding increase in silica and iron. 
The increase in iron was notably large, and there were other changes 
which seemed to show a marked antiquity of the remains.^ However, 
the close resemblance of these remains to recent Indian bones appears 
to contradict the chemical evidence. 

In consequence of the importance of the find the locality was 
visited by Vaughan. His report, which is summarized below, was 
published in full in the paper cited above.^ 

Osprey is situated on a narrow tongue of land rising some 15 to 20 feet above sea 
level, about one-third of a mile long and from 100 to 150 feet wide. The ridge of the 

» Unpublished manuscript, Carnegie Inst. Washington, 1913. 

2 For a partial list of these papers, see Moore, C. B., Jour. Acad. Nat. Sci., vol. 13, 1908. 
^Hrdlicka, Ales, Slieletal remains in North America: Bull. Smithsonian Institution, Bureau of Ameri- 
can Ethnology, No. 33, 1907, pp. 53-64. 
* Idem, p. 57. 
5 Idem, pp. 64-66, 



GEOLOGY OF NORTHERN AND CENTRAL FLORIDA. 163 

tongue is formed by an Indian shell mound. There is an Indian burial mound at its 
base, on its northeast side, and about one-fourth of a mile east of Osprey. Portions 
of a skeleton enveloped and partly replaced by limonite were found at this locality. 
Dr. Hrdlicka had a pit about 3^ feet deep dug at this place and exposed the following 
section : 

Section one-fourth mile east of Osprey. 

Inches. 
4. Black soil, about 12 

3. Grayish or white sand, about 24 

2. Irregular bed of yellowish sand, continuous with the 

above A few. 

1, Greenish, argillaceous, and sandy layer Unknown. 

The yellowish sand is the layer in which the skeleton was found. 
A study of the lower end of the shell mound on its side next to the bay gave the 
following section: 

Section of Indian shell mound near Osprey. 

Inches. 

4. Black soil Several. 

3. Shells, numerous species, all of which are Recent, 

about 48 

2. The base of the mound contains shells, many of which 

are cemented together and filled with ferruginous 
sandstone; others are filled v/ith greenish sand. 
All stages from the green sand to the ferruginous 
sandstone are represented. The layer is not uni- 
formly developed, occurring only in places 6 

1. Green sand to the water level in the bay Undetermined. 

A collection of shells was made from Nos. 2 and 3 of the section and were deter- 
mined by Dr. Wm. H. Dall. All the species found in No. 2 were also found in 
No. 3, and all of them are Recent. The geologic age of 2 and 3 is post-Pleistocene. 
Both from the contained fossils and stratigraphic relations they are younger than the 
Pleistocene of North Creek. The material in which the fossil human remains were 
found in the old burial mound seems to correspond to the ferruginous layer at the base 
of the shell mound and can scarcely be older — that is, the human remains are post- 
Pleistocene in age. 

No importance can be attached to the fossilized condition of the human remains 
found at any one of the three localities studied. At Osprey, where paleontologic and 
stratigraphic evidence is available, the evidence is in favor of the human remains 
being geologically recent. Positive paleontologic and stratigraphic evidence is absent 
at the locality between 1 and 2 miles south of Osprey and at Hanson's landing. In 
each locality there is no evidence to favor the remains being geologically as old even 
as Pleistocene. All of the positive evidence and the conditions under which these 
fossilized human bones were found in Florida favor the opinion that man geologically 
is a recent immigrant into that area. 

STRUCTTJIIE. 

EARLY INVESTIGATIONS. 

One of the earliest discussions of the structure of Florida was written 
by Johnson ^ in 1888. Though hampered by lack of detailed knowl- 
edge of the stratigraphy, he presented much evidence to show that 

1 Johnson, L. C, Am. Jour. Sci., 3d ser., vol. 36, 1888, pp. 230-236. 



164 GEOLOGY AND GROUND WATERS OF FLORIDA. 

the peninsula is a broad anticline. The conclusion reached by him 
was, in a general way, the same as that of several subsequent writers. 
His paper is accompanied by a section of the strata across the north- 
ern end of the peninsula showing a broad arch with the apex in the 
vicinity of Gainesville. The location of the crest of the arch was 
recognized by the sink-hole topography, which was thought to indi- 
cate the presence of ^'Eocene" (Oligocene) limestone (of the Vicks burg 
group) within less than 100 feet of the surface, and the dips away from 
the central part of the peninsula were determined by noting the pres- 
ence of younger formations at the surface and by the altitude of the 
Oligocene beds in wells at different points. 

About two years after the appearance of Johnson's paper Shaler ^ 
published a brief discussion of the topography of Florida, and in the 
same article stated his ideas of the structure of the State. Shaler 
appears to have regarded the peninsula as a broad arch, which he 
likened to the Cincinnati anticline: 

The first question before us concerns the origin of the Florida uplift. It will be 
observed that we have on the peninsula of Florida a very remarkable ridge, which has 
grown up from the sea floor to the altitude of about 5,000 feet, and a somewhat similar 
elevation in the archipelago of the Bahama Islands. Neither of these ridges has a 
mountainous character. Indeed it is at first sight difficult to find the analogues of 
these great anticlinal-like folds in the existing structures of the land. They can 
hardly be classed with any of our known table-lands, for the reason that such eleva- 
tions are in all cases more or less associated with definite mountain folding. The 
only similar structure which is known to me is that exhibited in the "Cincinnati 
anticlinal," that well-known ridge extending from near Columbus, Ohio, to northern 
Alabama. This elevation in length and breadth may be compared to that of Florida, 
though it never had more than one-half the height of the Floridian peninsula. 

It should be remembered that there is to be included with the 
peninsula the submerged plateau which borders it on either side an< 
extends to the edge of the abyssmal depths of the ocean, and whei 
Shaler speaks of a broad earth arch he includes in it not only th^ 
land but this submarine plateau, which in places extends more thai 
150 miles beyond the coast and descends steeply to profound depths j 
In a later paper Shaler ^ reiterates the same view and states that h( 
regards Florida as a broad submarine fold, approximately 600 mil( 
in length, which has risen from a depth of about 5,000 feet. 

In commenting on Shaler's hypothesis Dall ^ says : 

In considering the topography of Florida it has been customary among geologist 
and others to speak of the "central ridge," ''elevated axis," and in the latest con^ 
tribution to the subject Prof. Shaler regards Florida as ''formed of lowlands risin| 
as a broad fold from the deep water on either side to a vast ridge, the top of which i^ 
relatively very flat, there being no indication of true mountain folding in any pa 

1 Shaler, N.'s., Topography of Florida: Biill. Mus. Corap. Zool. Harvard Coll., vol. 16, No. 7, 1890, pp. 
139-156. 

2 Shaler, N. S., Relation of mountain growth to formation of continents: Bull. Geol. Soc. America, 
vol. 5, 1894, p. 206. 

3 Bull. U. S. Geol. Survey No, 84, 1892, p. 87. 



GEOLOGY OF NORTHEHK AND CENTBAL FLOKIDA. 165 

of the area." In an extremely wide and general sense it is of course true that the 
peninsula forms a great fold, but in the ordinary and literal meaning of the words this 
description conveys an inaccurate idea of the structure of the region. 

Dall regards the structure of Florida as characterized by low folds 
approximately parallel to the general trend of the peninsula. By 
means of railroad profiles he finds indications of two weU-defined 
ridges, one near the Atlantic coast and another near the Gulf coast, 
and notes a third in the vicinity of Brooksville and Plant City. The 
eastern ridge, which forms the eastern boundary of the central '4ake 
basin," includes the weU-known ^^ Trail" ridge and was, he thought, 
composed of '' Miocene" rocks (probably intended to include the 
Ohgocene rocks belonging to the Apalachicola group, which were then 
known as Miocene) . The western ridge forms the western boundary 
of the central ^4ake basin" and passes through Lakeland. The theo- 
ries advanced by Dall and Johnson differ in one important point. 
Dall believes that the central lake basin is a syncHnal valley; Johnson 
held that this region, which he designates '^high hammocks" or 
^'lake region," represents the eroded apex of a broad arch. 

GENERAL CHARACTER OF THE STRUCTURE. 

The State as a whole is merely the southern extension of the 
Coastal Plain, and its history has in general been the same. Broadly, 
it includes two distinct axes of upHft which appear to extend in a 
general north-south direction. The outhne of the Vicksburgian 
limestone west of Apalachicola River indicates a gentle upHft, and 
field observations show that this Hmestone has there an altitude 
of about 75 to 100 feet over a considerable area. From this upHft 
the rock dips steeply to the south and west and more gently, but still 
perceptibly, to the southeast. Toward the north and northeast 
it rises to form the basis of the highlands of southern Georgia and 
Alabama and then gives place to the underlying Jackson, which out- 
crops farther north. The exact trend of the uphft which brought the 
hmestone of the Vicksburg group to its present altitude in west 
Florida is not known, but it is probably east of north. The peninsular 
portion of Florida represents a broad uplift, such as was postulated 
by Johnson and Shaler, and the comparison with the Cincinnati arch 
appears to be appropriate. The objection to the use of the term 
"anticHne" in connection with these broad uphfts is due to the fact 
that most geologists are incHned to associate the word with narrower 
archings of the strata, such as are common in the Appalachian or other 
closely folded regions. By the use of the term ^'arch" it is hoped 
that this objection will be removed. In the peninsula of Florida the 
arching of the beds has raised the lower Ohgocene to an altitude of 
more than 100 feet above sea level over considerable areas from the 



166 GEOLOGY AISTD GBOUND WATERS 6F ELOMDA. 

vicinity of Brooksville and Croom northward to and beyond Gaines- 
ville, Live Oak, and Lake City. Around the outcrops of the rocks 
belonging to the Vicksburg group, which have been exposed on 
account of the erosion of this arch, are the exposures of the forma- 
tions which comprise the Apalachicola group and younger beds. 
The rocks belonging to the Apalachicola group occupy a broad belt 
from Sarasota northward to the Georgia-Florida hne and extend 
westward to where it is overlapped by beds of Miocene age. On the 
eastern side of the central uphft the Apalachicola group occupies a 
much narrower area and within a short distance is buried beneath 
younger beds. Since there is httle difference in the thickness of the 
beds belonging to this group on the east and west sides of the arch, 
it may be readily inferred that the easterly dips are more steep than 
the westerly. 

The northern end of the arch which forms the peninsula pitches 
gently downward, so that the hmestones of the Vicksburg group 
dip below the surface north of Live Oak and Lake City and the 
formations comprising the Apalachicola group appear in the valley 
of Suwannee River. The southern end of the arch sinks gently 
beneath the younger formations so that the limestones of the Vicks- 
burg group lie several hundred feet below the surface in Lee County 
and at Key West, where they were encountered in driUing wells. 

The variation in the depth to rocks of OHgocene age along the east 
coast of Florida is probably due in part to local variations in the rate 
of dip and to minor folds. There appears to be httle doubt that 
any upheaval which produced the broad arch forming the peninsula 
of Florida would also produce minor arches or folds parallel to the 
direction of the main uphft, as well as minor folds transverse to the 
main arch. The satisfactory discrimination of these minor folds 
calls for a large amount of detailed stratigraphic work based on a 
knowledge of the fossils representing different horizons. It is possible 
that the ridges mentioned by Dall are really minor folds, but he does 
not appear to have ehminated the possibility of their being due to 
circumdenudation. That there are many minor folds in Florida 
can not be denied. Good examples of such folds are those which 
Dall ^ noted on Caloosahatchee River. These smaU folds are not 
more than 10 to 12 feet high and are mostly not more than one- 
fourth mile wide. They are of more than usual interest because 
they involve marls of Phocene age and hence were probably formed 
during Pleistocene or even Recent time. 

1 Notes on the geology of Florida: Am. Jour. Sci., 3d ser., vol. 34, 1887, p. 168; Tertiary fauna of Florida: 
Trans. Wagner Free Inst. Sci., vol. 3, pt. 6, 1903, p. 1604; Correlation papers— Neocene: Bull. U. S. Geol. 
Survey No. 84, 1892, p. 143. 



OIEOLOGY AND GKOXJND WATERS OF FLORIDA. 167 

GEOLOGY OF SOUTHERN FLORIDA. 

By Samuel Sanford. 

The general geologic structure of the Florida peninsula, the char- 
acter of the materials that underlie the surface, and the areal dis- 
tribution, relative position, and age of these materials have already 
been discussed (pp. 65-166) and will not be reviewed here, but as the 
topography of southern Florida, as a whole, is different from that of 
the central and northern parts of the State, so the geology has fea- 
tures which differentiate the region from the greater portion of the 
peninsula. 

STRATIGRAPHY. 

Except for a possible extension of Pliocene beds south of the ex- 
posures on Caloosahatchee River (p. 136), all the surficial formations 
of southern Florida, unconsolidated and consolidated, are of Quater- 
nary age and include those laid down in Recent and in Pleistocene 
time. 

PRE-PLEISTOCENE FORMATIONS. 
CHARACTER AND DISTRIBUTION. 

The outcrops of Oligocene, Miocene, and Pliocene beds in central 
and northern Florida and the relations of the beds have been dis- 
cussed (pp. 71-150). Neither Oligocene nor Miocene strata come 
to the surface in southern Florida and outcrops of Pliocene deposits 
are not known. ^ Hence the character, thickness, and relations of 
any beds older than Pleistocene must be inferred from what has 
been determined to the north or proved by samples collected from a 
number of scattered wells. But the nearest outcrops of Miocene 
and Oligocene beds are so far from the greater part of the area under 
discussion that inferences as to the character, thickness, and depth 
of Miocene or older beds are little better than guesses, and, unfortu- 
nately, reliable records of deep wells are few. Still, enough is known 
of the deeper-lying beds to permit the drawing of general conclusions 
as to the character and origin of the Miocene and Pliocene deposits. 

WELL RECORDS. 

DISTRIBUTION OP WELLS. 

On the east coast wells over 100 feet deep have been sunk at 
Gomez, 1,200 feet; Hobe Sound, 1,100 feet; West Jupiter, 101 feet; 
Palm Beach, 1,215 feet; Fort Lauderdale, 108 and 387 feet; and 
Delray, 119 feet. Along the line of the keys deep wells have been 
sunk at Indian Key, 135 feet; Indian Key Channel, 687 feet; Key 
Vaca, 700 feet; Knights Key, over 620 feet; Big Pine Key, 711 feet; 

1 That isolated patches of Pliocene beds, thinly hidden by Pleistocene sand, occur some distance south 
of Caloosahatchee River is regarded by the writer as highly probable. 



168 -GEOLOGY AND GEOUND WATERS OF FLORIDA. 

Key West, 500, over 900, and 2,398 feet. On the west coast there 
are wells at Marco, 376 feet; Estero, 285 feet; Punta Rasa, 140 
and 280 feet; St. James City, 148 and 335 feet; Sanibel Island, 420 
and over 600 feet; and Buck Key, 605 feet. In addition, wells 
have been sunk in the prairies south of Caloosahatchee River and 
west of Lake Okechobee as follows: T. 47 S., R. 31 E., 647 and 691 
feet; T. 48 S., R. 31 E., 720 feet; T. 46 S., R. 33 E., 921 feet. 

The logs of most of the wells mentioned were not recorded care- 
fully and the logs of several are not available. More or less con- 
tinuous series of samples were saved at Palm Beach, Indian Key 
Channel, Key Vaca, Key West, and Buck Key. 

PALM BEACH. 

Darton ^ gives the following record for the Palm Beach well: 

Record of well of C. I. Craigin, Palm Beach. 




Depth. 



Sands, with thm layers of semivitriiied sand at 50 and 60 feet 

Very fine gramed, soft, greenish-gray quartz sand, containing occasional Foraminifera 
and waterworn shell fragments 

No sample 

White sand, with abundant Foraminifera of four or five species 

No sample 

Gray sand, containing shark's teeth, small waterworn shells, and bone fragments, 
sea-urchin spines, and lithifled sand fragments 

No sample 

Samples at frequent intervals: Vicksburgian limestone containing Orbitoides in 
abundance throughout, together with occasional indeterminable fragments of 
moUuskan casts, corals, and echinoderms. It is a creamy white, hard, homogene- 
ous limestone throughout 



Feet. 
400 



850 
860 
904 



915 
1,000 



1,212 



Darton was unable to determine definitely the age of the series 
overlying the limestones, but the organic remains from 800 to 915 
feet suggest Miocene age, and the Foraminifera between 400 and 
800 feet indicate that the beds whence they came are also probably 
of Miocene age. 

This record shows that the top of the Vicksburg group (lower 
Oligocene) lies between 915 and 1,000 feet below the surface at 
Palm Beach. The great thickness of quartz sand is the most note- 
worthy feature of the record. 



INDIAN KEY CHANNEL. 



The followiQg log of the well at Indian Key Channel, on the grade 
of the Florida East Coast Railway (sec. 12, T. 64 S., R. 36 E.), is of 
more than average value, as the driller kept notes and saved a good 
series of samples. The latter were examined by Vaughan and some 
of his comments are given in parentheses after the driller's notes. 
The tentative correlation of the strata is also by Vaughan, who 
based his determinations on a few recognizable and distinctive fossils. 

1 Darton, N. H., Am. Jour. Sci., 3d ser., vol. 41, 1891, pp. 105-106. 



GEOLOGY OF SOUTHERN FLORIDA. 

Record of well at Indian Key Channel. 



169 



Thickness. 



Depth. 



Pleistocene, including Recent: 

Marl, soft, white 

Hard rock (white limestone) 

Rock, soft, and marl (yellow siliceous and calcareous sand, with Porites fragments. 
Pliocene: 

Rock, soft, and marl (siliceous and calcareous sand), with pieces of hard limestone . 

Rock, hard, gray (hard limestone, little or no silica) 

Rock, medium hard, gray (hard limestone; fossil shells) 

Pliocene and Miocene: 

Sand, white (fine, white, calcareous and siliceous, 144-155 feet; gray, siliceous and 
calcareous, 155 to 255 feet; fossil shells at 155 to 175 feet) 

Sand, gray, and shells (coarse sand with thin calcareous tests) 

Sand, gray (fine yellowish with a few calcareous fragments) 

Sand, white (fine, gray, with a few calcareous fragments, 295-315 feet; coarser, 
yellowish, with a few quartz pebbles 3 to 4 mm. long, 315-355 feet; gray sand, 
355-395 feet; fine, gray sand with mica flakes, 395-415 feet; same with calcare- 
ous fragments, 415-425 feet; gray sand with some calcareous fragments, 435- 
475 feet) 

Sand, yellow (gray, with calcareous fragments) 

Sand, gray 

Sand, white (gray, slightly yellowish, with mica flakes, 515-535 feet; very coarse, 
yellowish and gray, with shell fragments, 535-555 feet; fine, gray, a few coarse 

grains, with mica fl^akes, 555-575 feet) 

Oligocene (Apalachicola group): 

Sand, with about 12 inches of blue clay (coarse gray sand, blue clay, numerous 
unidentifiable shell fragments) 

Rock, soft, white, clay, and sand (cream-colored limestone, with shell fragments 
at 604 feet) 

Lime formation, soft, clay and sand (siliceous limestone) 

Lime formation, soft rock (cream-colored marl, with a few grains of silica) 

Lime formation, with sand (gray siliceous sand with numerous calcareous par- 
ticles ) 

Rock (yellowish limestone and coarse siliceous sand) 

Soft rock (yellowish limestone) 



Feet. 



112 
20 
20 



180 
20 
20 



Feet. 



128 
137 
143 



255 
275 
295 



475 
495 
515 



575 



4 


608 


27 


635 


3 


638 


7 


645 


2 


647 


40 


687 



The predominance of sandy beds is a noteworthy feature of this 
section. 



KEY VACA. 



Two wells were drilled at Marathon, near the west end of Key 
Vaca, one to a depth of 534 feet and the other to about 700 feet. 
The combined records of the two wells gives the following section : 

Record of wells at Marathon. 



Reef rock; amorphous to crystalline, white or yellowish limestone of varying hard- 
ness; full of heads of corals, chiefly Meandra and Orbicella; with Porites fragments 
at 82 and 101 feet; some corals replaced by calc spar; molds and casts of lithodomes; 
in places cemented shells and shell fragments, with molds and casts; soft layer at 
90 feet 

Marl, white, and hard, white and yellowish limestone; branches of Porites, 105-107 
feet; hard white limestone, 125-138 feet; grains of silica at 140 feet 

Limestone, soft, white, with shell casts and molds 

Limestone, medium hard, white; shell fragments, casts, and molds 

Limestone, soft, white, sandy; siliceous grains; proportion of sand increasing with 
depth; shell fragments, casts, and molds 

Quartz sand, medium fine, white; containing numerous irregular nodules with yel- 
lowish marly sand at 210-215 feet 

Quartz sands; in varying proportions of limy clay; quartz grains colorless; clay yel- 
lowish to dark green; streaks and layers of friable greenish sandstone containing 
shell casts and molds; bed of oyster shells at 240 feet 

Quartz sands, and soft, friable greenish sandstone containing shell casts and molds; 
streaks of dark-green limy clay, 306-310 feet; beds of shells, few determinable, prob- 
ably Miocene, 380-390 feet and at 400 feet 

Quartz sands, with greenish limy clay below 230 feet, and soft greenish sandstone; 
gravel bed with much- worn auartzose pebbles up to 40 millimeters long; tougli 
dark-green limy clay, 407-410 feet 

Quartz sands, generally greenish from limy clay; little sandstone; few streaks of 
tough dark-green clay; few fossils 



Thickness. 


Depth. 


Feet. 


Feet. 


105 


105 


23 


148 


2 


150 


5 


155 


21 


176 


54 


230 



70 



20 
280± 



300 



420 
700± 



170 GEOLOGY AKD GEOUND WATERS OF FLORIDA. 

Although the many samples of drillings from this well show the 
lithology of the formations penetrated, they give unsatisfactory 
evidence as to geologic age. The sands below 176 feet yielded but a. 
small variety of determinable fossils. A few claws or carapaces of a 
small crab or a few barnacle plates were the ojily organic remains 
noted in going through many feet of sand. The friable sandstones 
contained many casts, internal and external, of pelecypod shells, the 
external casts being of sandstone, the internal of more clayey mate- 
rial. These casts, though numerous, were not sharp enough to be of 
diagnostic value. 

The shell beds yielded a small variety of species; from collections 
between 375 and 420 feet Vaughan identified 5 species, including 
pectens and an oyster, which were probably Miocene. 

Thus the Key Vaca section, though it shows Pleistocene lime- 
stone and Miocene sands, gives no data for separating Pliocene from 
Miocene. The top of the Pliocene may be at 155 feet. The coarse- 
ness of the sands, their barrenness, and the character of the few 
determinable fossils between 176 and 400 feet indicate shoal water 
and strong currents. No break in deposition is determinable. 

KNIGHTS KEY. 

Little information is available regarding the well on Knights Key, 
about a mile west of Marathon. It went through the bed of Key 
Largo limestone, the limy beds, and the great thickness of sands 
below, and struck soHd limy sandstone underlain by limestone at 
620 feet. A few fossils brought up between 620 and 720 feet were 
examined by Vaughan, who reported that they were probably of 
Miocene age. 

BIG PINE KEY. 

The well on Big Pine Key is reported to have gone through the 
surficial limestones and struck fine sands with a considerable propor- 
tion of clay (or calcareous mud), much like the sands under Key 
Vaca, at a depth of 125 feet. Work stopped at 711 feet because the 
driUer was unable to go deeper with his rig. 

KEY WEST. 

Samples collected at 25-feet intervals from the deep well at Key 
West were examined by E. O. Hovey.^ The following generalized log 
is from his detailed description of the samples down to 2,000 feet: 

1 Hovey, E. C, Notes on the artesian well sunk at Key West, Florida, in 1895: Bull. Mus. Comp. Zool. 
Harvard Coll., vol. 38, No. 2, 1896, pp. 65-91. 



GEOLOGY OF SOUTHERl^ FLORIDA. 

Record of well at Key West. 



171 




Depth. 



Oolite, yellowish 

Limestone, white, yellowish, or light gray; with oolitic lumps 

Lime sandrock, fine, white 

Limestone, white, porous, oolitic, and sandy 

Limestone-, white, more or less solid 

Lime sandrock, friable, soft, gray 

Lime sandrock, yellowish to brownish; Orbitoides 800-850 feet 

Limestone, light gray; partly dense and partly porous 

Lime sandrock, gray 

Lime sandrock, yellowish gray; some porous limestone 

Lime sandrock, varying in color and compactness; strata of dense limestone . . . 
Limestone, yellowish to light-brownish gray; rather solid, with porous portions 



Feet. 

25 

175 

200 

275 

375 

675 

1,075 

1,175 

1,350 

1,450 

1,975 

2,000 



Aside from the depth, this log is notable for absence of beds of 
quartz sand, though such beds have a total thickness of over 400 
feet at Key Vaca, and over 200 feet at Big Pine Key, which are 
respectively 40 miles and 25 miles to the east. Certain peculiarities 
of the samples described by Hovey, taken with the reported incom- 
plete casing of the well, throw doubt on the value of the record, but 
probably no considerable bed of quartz sand was penetrated. 

The general aspect of the organic remains, bits of molluskan shells, 
corals, Foraminifera, echinoids, and coralline Algae, led Hovey to 
believe that the rocks originally were shoal- water deposits. The 
samples show that during Miocene and Pliocene time, as during 
Pleistocene and Eecent time, quartz sands did not get as far south 
and west as Key West. Hovey thought the Pleistocene beds at Key 
West might be less than 50 feet thick but was unable to separate the 
Pliocene and the Miocene. The top of the Vicksburg group he placed 
at 700 feet, thus making the total thickness of the Pliocene and Mio- 
cene less than 650 feet. 

Other samples from this deep well, probably portions of a duplicate 
series, were examined by Eldridge, whose determinations, contained 
in his unpublished notes, agree in general with those of Hovey except 
with regard to the presence of Orbitoides. Eldridge noted in samples 
below 7@0 feet abundant remains of Foraminifera of several species, 
but apparently did not recognize Orbitoides in a single sample. 
Evidently the samples examined by Eldridge, like those examined 
by Hovey, contained no quartz sands. A summary of Eldridge's 
notes on the samples is : 

Summary of record of deep well at Key West (by Eldridge). 




Depth. 



Limestone, oolitic beds, harder nonoolltic beds, streaks or masses of secondary calcite, 

and shell beds 

Sand, gray, calcareous 

Limestones, soft to hard, white to gray or brown, abounding in Foraminifera; a few 
beds of shells and calcareous sand 



Feet. 
375 

700 

2,000 



172 GEOLOGY AND GEOUND WATEKS OF FLOEIDA. 

Another deep well was sunk at Key West in 1908-9. Samples 
were saved from it at irregular intervals, from the surface to a depth of 
960 feet. They were not taken closely enough for the compiling of 
a good record, and most of the material saved was finely divided 
and contained very few determinable organic remains. The sam- 
ples are of interest, however, for the additional information they 
give regarding the substructure of the western end of the chain of 
keys. In general the agreement at specific depths with Hovey's 
description of samples from the well sunk in 1895 is not close. The 
materials brought up comprise oolitic and nonoolitic limestone, marls, 
calcareous sands, and sands containing a larger proportion of sili- 
ceous material than those described by Hovey. Samples from dif- 
ferent depths were examined by Vaughan, Sellards, and the writer. 
Taken as a whole the samples from the surface to 350 feet are oolitic 
and nonoolitic limestone showing no decided nor persistent change. 
From 350 to 500 feet the samples contain some soft, yellowish, 
greenish, or gray calcareous material. Fragments of oolitic lime- 
stone appear in the samples from 350 to 475 feet, and fine siliceous 
sand grains at 530 and 540 feet. From 540 to 710 feet no samples 
were saved. At 710 feet the material was much the same as at 540 
feet. A dark, firm, nonoolitic limestone, apparently struck at 786 
and continuing to 950 feet, contained many comminuted fragments 
of shells and some siliceous grains. At 960 feet the limestone was 
softer and white, with shell fragments but very few siliceous grains. 
The notable characteristic of the samples below 710 feet is the absence 
of determinable remains of Orbitoides. Though some of the samples 
contained fine siliceous sand grains, there is no evidence that the 
well penetrated any thick arenaceous beds. 

Summary of record of 1908-9 Key West well. 





Thickness. 


Depth. 


Limestone, oolitic and nonoolitic layers, and layers composed largely of shell frag- 
ments 


Feet. 
350 

436 

174 


Feet. 
350 


Marls and calcareous sands, with a very little siliceous sand and some layers of lime- 
stone 


786 


Limestone, containing many shell fragments; streaks or layers of softer calcareous 
material 


960 







BUCK KEY. 



A record of the Buck Key well, given from memory by the drUler, 
W. Sykes, of Fort Myers, supplemented by samples saved at different 
depths, furnishes the following section: 



GEOLOGY OF SOUTHEKN FLORIDA. 173 

Record of well of W. H. Knowles at Buck Key. 



Sand and shells 

Limestone, brown, crystalline; with cherty streaks and sand grains 

Quartz sand, white; with marl and shell fragments 

Limestone, orownish, sandy; with shell fragments 

Marl, dark greenish 

Quartz sand, white; with shell bed at 150 feet 

Sand, medium dark greenish, marly, with shell beds; and streaks of lighter marl 

Limestone, white to brownish and soft to hard; a few shell casts; hard brownish 
limestone containing many siliceous grains * 



Thickness. 



Feet. 


Feet. 


50 


50 


10 


60 


3 


63 


2 


65 


80 


145 


130 


275 


215 


490 



115 



Depth. 



605 



The thickness of the sands and marls and the small proportion 
of hard rock above 490 feet are the striking features of the section. 

OLIGOCENE SERIES. 

Foraminifera of the genus Orbitoides, which characterizes the 
Vicksburg group, were found in drillings from the wells at Palm 
Beach and Key West. The top of the limestone may lie about 950 
feet below the surface at Palm Beach and 700 feet below at Key 
West. An eastward dip of the limestone is indicated by the records 
of wells east of Fort Myers, but evidence to show the amount of dip 
is meager. A southern prolongation of the anticlinal fold of west 
central Florida is probable, but can not be established from the 
known data. 

Samples from the Palm Beach well showed Orbitoides for 312 feet; 
samples from the Key West well, according to Hovey, showed the 
same fossils at 750 feet and below. It is fairly certain that the 
latter well was not cased below 1,000 feet; hence little reliance can 
be placed on the samples from 1,000 to 2,000 feet. Thus no evi- 
dence to establish the thickness of the Vicksburg group is available, 
though Hovey noted changes in the character of the limestones at 
1,475 and 2,000 feet. Evidence to establish the thickness of Oligo- 
cene beds above the Vicksburg group is also lacking. 

MIOCENE AND PLIOCENE SERIES. 

A comparison of records from points so widely separated as Palm 
Beach, Key Vaca, and Buck Key shows a surprising thickness of 
beds composed largely of quartz sand, and contradicts the old belief 
that the southern end of the peninsula rests on a solid limy founda- 
tion. Between the surficial limestones and the limestones of upper 
Oligocene age are 200 to 900 feet of unconsolidated material that is 
more predominantly siliceous than calcareous. The succession of 
limy beds at Key West is explainable by remoteness from the main- 
land and consequently from the source of the quartz sands. 

No deep well in southern Florida has proved definitely the thick- 
ness of Miocene and Pliocene sediments at a given point, and it is 



174 GEOLOGY AND GROUND WATEES OF FLOEIDA. 

doubtful if any well that may be drilled will show Miocene deposits 
sharply separated from Pliocene or if wells in most of the region will 
afford a basis for separating the Miocene from the upper beds of the 
Oligocene. Hence the total combined thickness of the Pliocene and 
Miocene beds is likely to remain conjectural. It may amount to 
over 800 feet at Miami. 

Some of the Miocene and Pliocene sands probably represent siliceous 
grains derived by weathering and erosion from the upper Oligocene 
and lower Oligocene limestones. Much more of it may have worked 
south along the east and west coast of the peninsula or around the 
shores of the islands that foreshadowed the peninsula. The quartz 
grains no doubt were halted many times in the form of beds of sand, 
sandy marl, and even sandy limestones in their journey from their 
parent ledges to the south end of the peninsula. They were worked 
over again and again and even roughly concentrated in their south- 
ward drift, so that the mass of siliceous material at the south end of 
the peninsula represents the removal and assortment of many times 
its bulk of quartz-bearing rock. The process of concentration 
apparently continued through the Miocene and Pliocene epochs a 
sufficient length of time for the accumulation of hundreds of feet of 
sandy material. Only a depression of the coast and the substitu- 
tion of offshore for near-shore deposits or a change that would 
greatly increase the deposition of calcareous material would inter- 
rupt the process. There is no evidence of the iaterruption of the 
sands under Key Vaca. 

PLEISTOCENE SERIES. 
UNEXPOSED FORMATIONS. 

Of Pleistocene formations earlier than the limestones and sands to 
be described the only positive evidence at hand is that of well 
samples. A few records show a considerable thickness of Pleistocene 
material. Thus a bed of coquina at a depth of 118 feet in a well at 
Delray yielded 24 species of moUusks and 2 of corals (nonreef-builders) , 
of which 90 per cent were identified as Recent by Vaughan, indicating 
that the age of the coquina was early Pleistocene, earlier than the 
Miami oolite. Few samples have been taken from other east coast 
wells between depths of 100 and 200 feet. Samples from the well 
on Key Vaca indicated reef rock to 105 feet. At Key West lime- 
stones, evidently of shoal-water origin, are indicated by the samples 
from the deep well, but the thickness of Pleistocene beds earlier than 
the surface oolite is uncertain. On the west coast rather fine quartz 
sand underlies the Lostmans River limestone at Everglade. This 
sand is at least 40 feet thick. No samples were saved from the 
deep well at Marco and but few from the wells at the mouth of 



GEOLOGY OF SOUTHEEN FLOKIDA. 175 

Caloosahatchee River. The latter show sands and marls to a depth 
of over 100 feet. 

The notable feature of the well records is the reported finding of 
sands and unconsolidated material below hard rock at widely sepa- 
rated localities. Samples from West Palm Beach, 55 to 75 feet, show 
much- worn shell fragments, cemented and replaced by crystalline 
calcite, with pockets or beds of quartz sand but no hard rock close 
to surface. Samples from Miami show much the same variety of 
material below the surficial oolite. 

EXPOSED PLEISTOCENE FORMATIONS. 
GENERAL CHARACTER. 

The Pleistocene surficial deposits comprise limestones, coquina, 
shell marls, and sands. The limestones form bare ridges and occur as 
iaconspicuous scattered outcrops. The coquina lies along or back 
of many miles of ocean beach on the east coast, and the sands mantle 
the surface of the greater part of the pine land. 

The limestones described on the following pages are alike in being 
of marine origin, but nonmarrae limestones probably occur. Dall 
has mentioned the findiag of hard ringiag eolian limestone on Cork- 
screw Creek southeast of the mouth of Caloosahatchee River, and 
scattered deposits corresponding to the Planorbis rock of Dall will 
probably be found toward Lake Okechobee or between Caloosa- 
hatchee River and the Big Cypress. In the localities visited by the 
writer, however, but one occurrence of a possibly nonmarine lime- 
stone was noted — a soft, loosely compacted rock lying in lumps in the 
flatlands over an area but a few rods across, 3 miles west of West 
Palm Beach. 

The marine limestones seen are classified on the basis of lithology 
and areal extent as the Palm Beach limestone, Miami oolite, Key 
West oolite, Key Largo limestone, and Lostmans River limestone.^ 

PALM BEACH LIMESTONE. 

Synonymy. — References to the limestone on the east side of the 
Everglades and to limestone forming the eastern rim appear in 
various early accounts of travelers and of Arony officers who traversed 
the Everglades, but no distinctive term has been applied by anyone, so 
far as is known, to the inconspicuous outcrops of limestone sparsely 
scattered through the pineland, cypress swamp, and prairie along the 
eastern side of the Everglades, from Delray northward. The term 

1 Evidence not available at the time this classification was made indicates that the boundary between 
areas underlain by the Lostmans River limestone and the Palm Beach limestone can not be determined 
with precision in the Everglades, and there is good reason for believing that the oolites grade into limestones 
that are not oolitic. But the writer adheres to the classification here stated for the reason that he has not 
had opportunity to revise it in the light of the evidence to be gained by a careful examination of the material 
excavated along the miles of drainage canals dug during the past five years. 

76854°— wsp 319—13 12 



176 GEOLOGY AND GROUND WATERS OF FLORIDA. 

Palm Beach limestone is here used to distinguish these nonoolitic ma- 
rine limestones because the outcrops are found throughout a consider- 
able extent of country in the northeastern part of Palm Beach County. 
No similar rock outcrops near the town of Palm Beach. Though the 
outcrops are few and separated, it is possible that the limestone 
extends northward into St. Lucie County and is the equivalent of 
limestones elsewhere described. 

StratigrapJiic position. — As the exposures are all low, consisting of 
mere heads of rock projecting a few inches to a foot above the sur- 
rounding sands, and as none of the rivers, so far as reported, show 
good sections, little is known of the stratigraphic relations of the 
Palm Beach limestone. It is overlain by the sands of the pinelands 
and by the sands and peat of the Everglades. It is underlain, so 
far as can be told from the records of the few wells that have pene- 
trated it, by marl and sand. 

Seaward it grades into coarser and less solid rock or sand, overlain 
by the coquina deposits forming the backbone of some of the barrier 
beaches of the east coast. The limestone has not been seen in con- 
tact with the coquina and the exact relations remain to be ascer- 
tained. Some of the coquina may represent beach and bar deposits 
formed at the same time as the limestone. To the south, the lime- 
stone seems to grade into the Miami oolite, but the two have not 
beeii seen in contact. 

Lithologic character. — At the type locality in T. 45 S., R. 42 E., 
8 miles west of Hypoluxo, the rock is a white to yellowish limestone, 
containing a variable proportion of fine to medium quartz sand. 
The lime cement is not coarsely crystalline, nor does the rock con- 
tain, like other limestones of southern Florida, many patches and 
streaks of coarsely crystalline calcite, replacing amorphous material 
or filling cavities left by the solution of shell fragments. Its hard- 
ness varies greatly. In some places it is compact and dense, ringing 
under the hammer; in other places it contains so much sand that it 
is really a friable calcareous sandstone. 

Thiclcness. — Owing to the low elevation of the belt of country 
where the outcrops are found and the horizontal position of the 
limestone, the only evidence available to determine its thickness is 
that of well records. The testimony of these is contradictory, as is 
to be expected from the fact that most of them are given from 
memory. Such evidence as can be had, however, indicates that the 
limestone may be 5 to 50 feet thick. 

PJiysiograpTiic expression. — From the low relief of the pinelands 
and the monotonous flatness of the ground, it can not be said of the 
Pahn Beach limestone that it contributes to the physiography of the 
country. It helps, however, to define the eastern boundary of the 
Everglades for possibly 30 miles. 



GEOLOGY OF SOUTHERN FLORIDA. 177 

Paleontologic character. — The Palm Beach limestone is, as a whole, 
abundantly fpssiliferous. The fossils comprise gastropod and pelecy- 
pod shells, all of marine type and probably of living species. Corals, 
as is to be expected from the sandy character of the limestone, are 
few or altogether lacking. In places, the rock is full of shells of 
Ohione cancellata, well bedded, with the valves closed, indicating that 
the shells had not been disturbed since the moUusks died. The lime- 
stone thus has the facies of a shallow-water deposit formed in bays 
or lagoons with bottoms of sand or sandy marl. 

Areal distribution. — The northernmost exposure of the Miami oolite 
seen by the writer was in T. 47 S., R. 42 E., 5 miles south and 7 miles 
west of Delray. The southernmost exposure of nonoolitic limestone 
seen is about 5 miles north of Delray. There arc outcrops between, 
but they are scattered and were not visited, as it was thought doubtful 
that any direct transition from oolitic to nonoolitic beds could be 
found or any line of demarcation established. The northern limits of 
the formation are undefined. As before stated, it probably extends 
into St. Lucie County. Little is known of its western extent under 
the Everglades, but similar rock is found 7 to 1 1 miles west of Fort 
Lauderdale, along the drainage canal. To seaward it is buried by 
or grades into sand and coquina. 

Structure. — The rock is not as distinctly cross-bedded as are many 
exposures of the Miami oolite and the beds are more massive. The 
sandy layers at the type locality west of Lantana are 2 to 3 inches 
thick, and the limy beds may be a foot or more thick. 

MIAMI OOLITE. 

Synonymy. — The outcrops of oolite at New River, Miami River, 
Long Key in the Everglades, and at other points in southeastern 
Florida were noted by Army officers at the time of the Seminole War. 
The first writer to recognize the age of the deposits appears to have 
been Buckingham Smith, who in 1847 noted the many shells of 
mollusks in the oolite at Miami River and determined the age as 
post-PHocene.* 

In 1851 Tuomey described outcrops of the rock, on Miami River, ^ 
and in the same year L. Agassiz mentioned them in his account of the 
Florida reefs.^ 

Shaler* in 1890, following the views of L. Agassiz, regarded the 
oolitic limestones at New River and Cocoanut Grove as forming a 

1 Smith, BuckiBgham, Report on reconnaissance of the Everglades, made to the Secretary of the Treas- 
ury, June, 1848. 

2 Tuomey, Michael, Notice of the geology of the Florida keys and of the southern coast of Florida: Am. 
Jour. Sci., 2d ser., vol. 11, 1851, pp. 390-394. 

3 Agassiz, Louis, Florida reefs, keys, and coast: U. S. Coast Survey Kept, for 1851; appendix 10, 1852, 
pp. 145-160. 

^ Shaler,N. S., The topography of Florida: Bull. Mus. Comp. Zool. Harvard Coll., vol. 16, No. 7, 1890, 
p. 143. 



178 GEOLOGY AND GEOUND WATEES OF FLOEIDA. 

coral reef and included it and other rock, possibly coquina, in his 
Miami reef. 

A. Agassiz in 1895 stated that he believed the limestones at Miami 
and Cocoanut Grove to be of eolian origin/ and in a paper published 
the following year gave his reasons in detail.^ His views were not 
accepted by Griswold, who saw the rock nob only along the water 
front but possibly 20 miles inland.^ All the exposures of oolitic 
limestone on the mainland of southeastern Florida are in this paper 
included under the designation of Miami oolite. 

StratigrapTiic position. — The relation of the Miami oolite to the 
other limestones described in this paper is not definitely established. 
The extent of the oolite north, south, and southwest is obscured by 
sand or swamp deposits. The rock is perhaps younger than the 
Palm Beach limestone and is younger than the lower part of the 
Key Largo limestone. It lies almost flat. Griswold saw an inter- 
stratification of oolitic and nonoolitic rock, the latter probably the 
same as that designated coquina in this paper, at Linton, 20 miles 
south of Palm Beach. 

Although the Miami oolite is so overlain by unconsolidated deposits 
that its field relations can not be determined with exactness, weU 
records and samples from a few wells show what is below it at several 
places. At Miami samples from the wells of the water company 
show that the oolite loses its typical appearance a few feet below sea 
level and rests on an irregularly cemented aggregate of shell frag- 
ments and quartz sand much like coquina. At Dania the oolite 
rests on '^blue mud with gravel"; at Fort Lauderdale it rests on 
^^sand." 

LitJiologic clmracler. — Typically the rock is a soft white oolitic 
limestone, containing streaks or thin irregular layers of calcite 
separating less crystalline streaks. The rock breaks with an irregular 
fracture, dresses nicely, hardens on exposure, and makes good road 
metal and building stone. The aspects of quarry and rock -cut 
faces are shown in Plate XTV, B. 

Hand specimens show that the oolite carries a varying proportion of 
quartz sand. The quartz grains are mostly small and angular to 
subangular in outline, but a few are large and rounded. On the 
average the grains are considerably smaller than the ovules of the 
oolite, which have a mean longest diameter of one-fourth to one-half 
millimeter. 

The proportion of quartz sand is greatest to the north. Along the 
drainage canal west of Fort Lauderdale streaks of sand in the oolite 

1 Agassiz, Alexander, Note on the Florida reef: Am, Jour. Sci., 3d ser., vol. 49, 1895, pp. 154-155. 

2 Agassiz, Alexander, The elevated reef of Florida: Bull. Mus. Comp. Zool. Harvard Coll., vol. 28, No. 2, 
1896, pp. 29-62. 

3 Griswold, L. S., Notes on the geology of southern Florida: Bull. Mus. Comp. Zool. Harvard Coll., voL 
28, No. 2, 1896, pp. 52-59. 



U. S. GEOLOGICAL SURVEY 



WATER-SUPPLY PAPER 319 PLATE XIV 



Im^... 










... 'a 



A. REEF ROCK, KEY LARGO LIMESTONE, SHOWING EROSION. 




B. QUARRY IN MIAMI OOLITE. 



GEOLOGY OF SOUTHEEK FLORIDA. 179 

are so loosely cemented that perfectly preserved shells of CUone 
cancellata can be picked out with the fingers, whereas at Long Siding 
quartz grains in the oolite are relatively rare. Besides being more 
plentiful to the north, the sand grains seem to form a larger propor- 
tion of the rock near Biscayne Bay than farther west, as on Long 
Key. 

Examination with the microscope shows that the ovules have a 
well-marked concentric structure; some have as nucleus a rounded 
aggregate of minute calcite crystals ; others have as nucleus a rounded 
aggregate less evidently crystalliae ; some are built around shell frag- 
ments and many around grains of quartz. The concentric layers 
vary in number from 1 to 5 and in appearance from clear and rather 
coarsely crystalline to opaque, the shade varyiQg with the amount 
of organic matter and amorphous material. 

Thickness.— ^A well at Fort Lauderdale, according to the driller, 
went through 12 feet of oolitic limestone, one at Dania 40 feet of 
oolite, and the wells of the Miami Water Co. about 15 feet. These 
figures, making due allowance for the scantiness of the data and the 
unreliability of well records unless accompanied by samples, show 
that the maximum thickness may be 50 feet along the coastal out- 
crops and perhaps less inland. 

PliysiograpJiic expression. — L. Agassiz and subsequent observers 
noted that the oolite ledges near Miami and Cocoanut Grove have a 
steep seaward face, forming a low cliff, and slope off in a succession 
of low ridges toward the Everglades. Shaler also noted along the 
bluff back of the present shore evidences of wave erosion that 
indicated an uplift of the coast. The ridges back from the bluff 
appear to have a general trend to west of north. The absence of 
soil, and the quality of the rock surface, indicate that these ridges 
are to be accounted for by original manner of deposition, or by ero- 
sion during uplift, and not by erosion since; yet, that there has been 
some removal of rock is proved by the potholes, large springs, and 
such water work as the Punch Bowl and the shallow gorge of Arch 
Creek. 

The maximum elevation of the ledges south of Miami may be 25 
feet above sea level. The maximum elevation on Long Key in the 
Everglades is about 8 feet and at New River about 8 feet. 

Paleontologic character. — The Miami oolite varies in content of well- 
preserved fossils but is a distinctly fossiliferous rock. The animal 
remains comprise molluscan shells, echinoids, and corals. The corals 
are not reef builders, and one at least is plentiful in the Bay of Florida 
to-day. Collections by Vaughan near Miami in the wdnter of 1907-8 
yielded 2 species of corals and 14 of mollusks, all 16 species being 
Recent. Of 26 species collected along the drainage ditch west of Fort 
Lauderdale by Matson in the same winter Vaughan specifically deter- 



180 GEOLOGY AND GEOUKD WATEKS OF FLOElDA. 

mined 20 as Kecent and 1 as Pliocene. Many small heads of coral 
(Siderastrea) were throwni up by the dredge. 

Areal distribution. — The most northern exposure of oolite known 
to the writer is west of Delray. The rock outcrops on Long Key and 
the neighboring keys in the Everglades for 15 miles west of the south- 
western corner of the Biscayne Pineland, and was found by Griswold 
at an estimated distance of 20 miles west of Miami. Its extent under 
the Everglades farther north, at Fort Lauderdale, is apparently slight. 
Samples dug up along the drainage canals show that the rock rim of 
the Everglades is oolite; but the rock found west of the narrow, and 
presumably shallow, sand-filled hollow inside the rim is not oolitic, 
judging from samples collected by the engineer in charge of the dredges. 

Structure. — At the type locality, Miami, the rock is plainly stratified 
and cross-bedded. (See PL XIV, B) The bedding is that of water- 
borne sediments. No regional tilt can be distinguished from the 
outcrops, though it is probable that the formation dips slightly west. 

Correlation. — The contemporaneous deposition of coquina and oolite 
suggested by Shaler and accepted by Griswold can not be proved from 
any outcrops seen by the writer, but the contemporaneous deposition 
of the two seems probable. 

Origin. — The origin of the Miami oolite is discussed in connection 
with that of the Key West oolite. (See pp. 182-184.) 

KEY WEST OOLITE. 

Synonymy. — The first distinctive reference to the rock here desig- 
nated Key West ooHte appears to be that of G. W. Featherstonhaugh, 
who at a meeting of the New York Lyceum of Natural History in 
September, 1828, exhibited samples of oolite from Key West.^ 

Conrad on his visit to the keys in 1847 ^ suggested the post-Phocene 
age of the rock. Tuomey, in 1850,^ noted the oolite and compared 
it to recent deposits along the keys, and L. Agassiz,^ in 1852, 
described the rock in some detail. Hunt believed that the ooHte had 
formed from the consohdation of hmy material similar to that 
accumulating about the keys, and A. Agassiz thought that the Key 
West oolite, like the Miami ooHte, had an eoHan origin. All the oohte 
outcropping on the keys south of Florida Bay is here designated the 
Key West oohte. 

StratigrapMc position. — On the south side of Big Pine Key and on 
one of the Newfound Harbor keys the Key West oolite apparently 
overlies the Key Largo limestone. Its relation to the nonoohtic rock 

1 Am. Jour. Sci., 1st ser., vol. 16, 1829, p. 206. 

2 Conrad, T. A,, Observations on the geology of a part of the coast of east Florida: Am. Jour. Sci., 2d 
ser., vol. 2, 1841, pp. 36-48. 

3 Tuomey, Michael, On the geology of the Florida keys: Am. Jour. Sci., 2d ser., vol. 11, 1851, p. 390. 

* Agassiz, Louis, Florida reefs, keys, and coast: Rept. U. S. Coast Survey for 1851, Appendix 10, 1852, pp. 
145-160. 



CEOLOGY of SOUTHEEN FLORIDA. 181 

called in this paper the Lostmans River limestone can not at present 
be determined, since the contact, or possibly the line of gradation, 
between the two Hes under the Bay of Florida. The oolite is over- 
lain by recent marls and calcareous sands and in places along the 
shores of the keys may have a thin veneer of beach rock. 

Liihologic character. — Typically the Key West oolite is a soft white 
or light-colored fossiliferous oolitic limestone, the ovules being scat- 
tered through amorphous carbonate of Hme or surrounded by a crys- 
talline cement that develops most freely along bedding planes. The 
ovules on the average have a longer diameter of about one-half milU- 
meter. The rock is less sandy than the Miami oohte but resembles 
the latter in general appearance and physical qualities, there being 
Httle difference between hand specimens of the two. 

Like the Key Largo limestone, the Key West oolite shows on many 
unweathered exposures a thin dark crust, finely banded, of more or 
less amorphous carbonate of lime. In this crust all traces of oohtic 
structure disappear. That this crust is due to deposition of limy 
ooze is shown by a slab of crust containing unmistakable mud cracks 
which was photographed by Vaughan (PL XV, B, p. 184). Much of 
the rock shows cross bedding, but not so conspicuously as does the 
Miami oohte. It is easily quarried and dressed and makes fair 
building stone and good road material. 

Under the microscope the ovules of the Key West rock resemble 
those of the Miami rock. The nuclei of the ovules are mostly rounded 
calcareous grains, though in some ovules a grain of quartz forms the 
nucleus. The general appearance of the ovules indicates a forma- 
tion in unconsolidated material in the presence of water. 

Thickness. — The maximum thickness of the Key West oolite is 
unknown. Several wells over 50 feet deep have been sunk at Key 
West, but from only one of these were many samples preserved. 
According to the driller a well sunk near the plant of the Consumers 
Ice Co. penetrated 65 feet of rock of the same general character as 
that at the surface. Samples from the deep well in Jackson Square 
have been described in much detail by E. O. Hovey.^ From them 
Hovey concluded that the Pleistocene rock at Key West was but 25 
to 50 feet thick. There can be no question as to the accuracy of 
Hovey' s description, but it seems doubtful whether the samples were 
taken and labeled with equal accuracy. Hence the evidence of the 
samples is not conclusive. East of Key West no section of greater 
depth can be had than those of the excavations along the line of the 
Florida East Coast Railway, and from none of these was material 
taken at a greater depth than 10 feet below sea level except in some 
of the crossings between the keys where the maximum depth may 

» Hovey, E. O., Notes on the artesian well sunk at Key West, Fla., in 1895: Bull. Mus. Comp. Zool. 
Harvard Coll., vol. 38, No. ?, 1896, pp. 65-91. 



182 GEOLOGY AND GEOUND WATEES OF FLOEIDA. 

have been more. So far as the writer knows, all the material 
extracted between Big Pine Key and Key West was oolitic. A well 
at Big Pine Key went through the oolite; the exact thickness there 
is uncertain but is probably less than 50 feet. 

Physiographic expression. — As the Key West oolite covers the 
islands west of Bahia Honda to Key West the distribution of the 
outcrops is quite different from that of the Key Largo limestone, the 
islands west of Bahia Honda lying in an irregularly triangular archi- 
pelago instead of in a long, thiQ line. The relief of these islands is 
nowhere 15 feet. The highest land on the largest of the islands, Big 
Pine, is but 13 feet above tide, as is the highest ground on Key West. 
On many of the keys between Big Pine Key and Key West bedrock 
barely reaches to sea level, the islands being low-lying flats of marl 
with many patches of mangrove swamp that are inundated to a depth 
of 5 feet during hurricanes. 

Like the Miami oolite the Key West oolite weathers easily, but its 
surface nowhere has the rough and jagged appearance of the rock in 
the Biscayne pineland. Roots have disrupted angular blocks, but 
the surface in general is smooth and areas as extensive as 100 square 
yards show no sign of roughening by decay. 

Small vertical holes of varying size and shallow hollows characterize 
the outcrops. Many of the holes communicate with underground- 
water channels, many of v/hich are larger than those found in the 
Key Largo limestone. In places these passages contain salt water a 
quarter of a mile or more from the shore line and therefore must be 
comparatively free openings of considerable extent. 

Paleontologic character. — The abundant marine fossils in the Key 
West oolite comprise remains of corals, echinoderms, and mollusks, 
with foraminifera and other less evident fossils. Collections made 
by Vaughan on Torch Key and by the writer on Big Pine Key give, 
according to Vaughan, a total of 26 species, of which 2 are corals, 1 an 
echinoid, and 23 mollusks. The corals were not of reef-building 
species, and Vaughan found several delicate pelecypod shells with 
both valves closed, indicating that the shells had not been rolled about 
much. A study of the exposures on Big Pine Key shows that the 
shells as a rule are but slightly worn. All the specimens are of living 
species. 

Origin. — The Miami and Key West oolites differ so slightly, the 
chief differences being the greater percentage of quartz grains and 
stronger cross beddiag near Miami, that they may be assumed to 
have had a common origin. Whether this was eolian or whether it 
was marine is a point of interest. The evidence comprises the field 
relations of the rocks, their appearance in outcrops, and their litho- 
logic and paleontologic characteristics. 



GEOLOGY OF SOtTTHEBiST FLORIDA. 183 

The oolites are thin. At Dania the Miami oolite overlie ''blue mud 
and gravel/' and at Miami it overlies quartz sand and worn shell 
fragments cemented by clear crystalline calcite separated by layers 
of sand containing nodules made of quartz grains. At Key West 
the oolite apparently overlie shallow water lime-sand rock. Nowhere 
has the Miami oolite been proved to rest on an old coral reef. 

Outcrops of oolite are not known north of Delray, on the east coast, 
or anywhere on the west coast. Though exposures form conspicuous 
bluffs near Miami and low ridges for a few miles west, yet much of the 
Miami oolite is flat topped, outcrops showing differences of less than 
5 feet in elevation for miles toward Long Key. Long Key itself is 
nowhere 10 feet above sea level. Nowhere on the mainland are 
ridges comparable with the dune ridges of siliceous sand at Hobe 
Sound. The fiat smooth tops of the oolite exposures in the keys west 
of Bahia Honda are one of their most striking features. 

The cross bedding of the oolites is more marked in some outcrops 
than in others; in some the cross bedding is not at all conspicuous, 
the best being near the ocean or the Florida Strait rather than 
inland. The writer believes the cross bedding is that of water-laid 
material; he can not see that it is like that of the wind-borne sands in 
such dunes as those at Cape Henry, Va. 

The oolite is abundantly fossiliferous, in places containing delicate 
shells with valves adherent, in places shells of some size and heavy 
heads of nonreef -building corals. Buckhorn corals (Po rites) so 
plentiful in present beach ridges of coral sand are uncommon in the 
oolite exposures seen by the writer. 

An oolite from China examined by Blackwelder,^ exhibited peculi- 
arities which indicate that the concentric structure of the ovules 
developed when the material composing the rock was loose and 
somewhat mobile — that is, was a calcareous mud. The microscopic 
structure of the Key West and Miami oolites suggests an underwater 
origin for the ovules. The rounded aggregates of amorphous carbon- 
ate of lime that serve as nuclei of many ovules are like aggregates 
now lying on the bottom of the Bay of Florida. Hunt thought he 
saw one case of incipient oolitization in marl at Key West. Vaughan 
has detected oolitic grains in muds and sands from about the keys. 

The characteristics of the calcareous sands and marls accumulating 
about the keys and in the Bay of Florida and the distribution, 
topographic relief, bedding, contained fossils, and structure of the 
Key West and Miami oolites indicate that the latter were originally 
limy muds, with a varying proportion of lime sand and a little quartz 
sand, which accimaulated on the bottom of shallow bays or lagoons, 
where the water was in places relatively still and in places agitated 

1 Willis, Bailey, and Blackwelder, Eliot, Research in China, Pub. Carnegie Inst. Washington No, 54, 
vol. 1, pt. 2, 1907, p. 380. 



184 GEOLOGY AKD GKOUND WATEKS 0^ f LOMDA. 

by waves and currents strong enough to build up and level off banks 
and bars, conditions approaching those that exist in many places 
about the koys. That oolites may be forming now in the Bay of 
Florida is possible. That they will be found in process of formation 
is not certain. Examination of material from the surface of banks 
will probably give negative results, examination of material buried 
for some time may give positive results. 

The exact method in which oolitic structure develops is not yet 
evident. Colloidal CaCOg, precipitated by organisms or by the 
action of an electrolyte, as salt water, tends to form such minute 
aggregates as occur on the bottom of the Bay of Florida and to 
adhere about grains of sand in a concentric layer. Consequently it 
is easy to see how a single-ring ovule can develop; but alternate 
crystalline and noncrystalline rings, 3 or 4 in all, of typical oolites 
imply secondary replacement of carbonate of lime and special condi- 
tions favoring replacement. 

Chemical character. — Chemically, except for silica included as 
grains or spicules and scattered cherty streaks, the oolites are almost 
pure carbonate of lime. The following analysis, published by Hovey, 
was of rock taken from the surface near the deep well in Jackson 
Square, Key West. 

Analysis of Key West oolite. 
[George Steiger, analyst.] 

Silica (SiOa) 0.17 

Alumina (AI2O3) .20 

Iron oxide (FeaOg) 07 

Lime (CaO) 54. 03 

Magnesia (MgO) 29 

Carbon dioxide (CO2) 42. 52 

KEY LARGO LIMESTONE. 

Synonymy. — The elevated reef that forms the backbone of the main 
chain of the Florida keys from Soldier Key to Bahia Honda has been 
recognized as made up of coralline material by practically all the 
writers who have described the keys in any detail. One of the first 
references is that of Henry Whiting, who called it a coralline lime- 
stone.^ 

The first reference to the keys representing an uplift is that of T. A. 
Conrad. He visited the islands in the winter of 1842, and besides cor- 
relating the evidences of elevation there with other evidences in 
northern Florida determined the age of the reef rock as post-Pliocene.^ 



1 Whiting, Henry, Cursory remarks on east Florida in 1838: Am. Jour. Sci., 1st ser., vol. 35, 1838, pp. 
47-64. 

2 Conrad, T. A., Observations on the geology of a part of east Florida: Am. Jour. Sci., 2d ser., vol. 2, 1846, 
pp. 36-48. 



U. S. GEOLOGICAL SURVEY 



WATER-SUPPLY PAPER 319 PLATE XV 




A. REEF ROCK, KEY LARGO LIMESTONE, CORAL HEAD. 




B. MUD CRACKS IN CRUSTAL LAYERS OF KEY WEST OOLITE. 



GEOLOGY Of SOUfHEKN FLOEIM. l85 

Tuomey visited the keys in 1850 and noticed the large heads of coral 
in the reef rock at Key Vaca, Indian Key, and elsewhere. (See PL 
XV, A.) He stated very clearly: '^ There can be no doubt that this 
great chain of keys is due to the elevation of a vast uneven coral reef 
whose prominent points rising above the water form the foundation 
of the keys, the sands driven up by the waves having done the rest." ^ 

L. Agassiz and Le Conte visited the keys in 1851. Agassiz gave an 
accurate description of the coral rocks, but positively denied the evi- 
dences of elevation seen by Conrad and Tuomey, believing that the 
coral bowlders had been thrown up by hurricanes and cemented by 
calcareous sands and mud — the keys having been built up to their 
present elevation above sea level purely by the action of the waves 
and winds — making the rock '^subaerial, not a marine accumula- 
tion.'' ^ 

This view of the rock above sea level having resulted from the 
cementation of material thrown up by the waves was shared by Hunt ^ 
and Le Conte.* 

In 1883 A. Agassiz published a paper on the keys in which he attrib- 
uted their western growth to a return eddy of the Gulf Stream, pre- 
viously postulated by Hunt, and said: ^ '^The line of keys seems to be 
formed by the waste of the exterior present reef rather than by the 
remains of an older reef." He recognized that the Tortugas were 
younger than the keys to the east, saying that the deposits composiug 
them ^'have not as yet been transformed into the normal coral rock." 

On a subsequent visit to the keys Agassiz saw the evidences of ele- 
vation and confirmed the conclusions of Tuomey.^ He elaborated 
his views of the growth of the keys in a comprehensive account of 
their geology and topography.^ 

The recent construction work of the Florida East Coast Railway 
has shown the character of the rock from the place where the raihoad 
bends southwest on Key Largo to the west end of Knights Key. 
Borrow pits expose the limestone, not only where it was lightly 
covered by leaf mold but where it was buried under several feet of 
marl and sand, and dredging has revealed its character where it lies, 
as in channels between the keys, 10 feet or more below sea level. 
Hence, the opportunities for observing the various phases of the 

1 Tuomey, Michael, Notice of the geology of the Florida keys and of the southern coast of Florida: Am. 
Jour. Sci., 2d ser., vol. 11, 1851, pp. 390-394. 

2 Agassiz, Louis, Florida reefs, keys, and coast: XJ. S. Coast S\irvey Rept. for 1851, appendix 10, 1852, pp. 
145-160. 

3 Hunt, E. B., On the origin, growth, substructure, and chronology of the Florida reef: U. S. Coast Sur- 
vey Rept. for 1862, appendix 25, pp. 241-248. 

* Le Conte, Joseph, On the agency of the Gulf Stream in the formation of the Peninsula of Florida: Proc. 
Am. Assoc. Adv. Sci., 1857, pt. 2, pp. 103-119. 

6 Agassiz, Alexander, The Tortugas and Florida reefs: Mem. Am. Acad., vol. 2, 1883, pp. 108-109. 
« Agassiz, Alexander, Note on the Florida reef: Am. Jour. Sci., 3d ser., vol. 49, 1895, pp. 154-155. 

7 Agassiz, Alexander, The elevated reef of Florida: Bull. Mas. Comp. Zool. Harvard Coll., vol, 28, No. 2, 
1896, pp. 26-62. 



186 GEOLOGY ANt) GROUND WATEES OE FLOEIDA. 

rock and for determining its origin are incomparably better than when 
A. Agassiz visited the ke3^s in 1894. 

On Key Largo cuts and borrow pits expose the limestone at 
short intervals from the south shore of Lake Surprise to the west 
end of the Island at Tavernier Creek, a distance of 15 miles. As this 
is the longest series of exposures on any of the keys, the reef rock is 
here designated the Key Largo limestone. 

StratigrapJbic position. — As the Key Largo limestone represents 
the only laiown fossil coral reef in southern Florida, it forms a litho- 
logic unit and is sharply differentiated from any of Ihe other lime- 
stones of the mainland and keys. Having been built up from the 
bottom from a depth of perhaps more than 100 feet during a consid- 
erable interval of time, it may in part be contemporaneous with the 
other limestones, and in part may be older, as these limestones are 
believed to represent shallow-water deposits, some of which accumu- 
lated behind the reef while the latter was growing and finally extended 
oyer it. In places the Key West oolite apparently rests on the Key 
Largo limestone; the relations to the Miami oolite and Lostmans 
River limestone are less certain. 

Lithologic character. — The Key Largo limestone is extremely vari- 
able in appearance and structure. Considered as a whole it greatly 
resembles the reef rock of the southern Pacific, described by Dana.' In 
some parts it is a coral conglomerate or breccia, made up of fragments 
firmly cemented. Over much larger areas it is a fine white limestone, 
as compact as any secondar}^ marble and as homogeneous in texture. 
It is often free from any traces of organic life or proofs of an organic 
origin. It breaks with conchoidal fracture, spUntery surface, and 
rings under the hammer. Other portions of the rock, of less extent, 
are made of standing corals with the uitervals filled in by reef debris, 
and the whole cemented solid. 

Though the Key Largo limestone represents an elevated coral reef, 
as is shown by the countless heads of reef-building corals, yet it is 
doubtful if more than a fourth of the total mass of the formation is 
derived from corals. Coralline algse undoubtedly contributed much 
calcareous material, but a great though undeterminable bulk of such 
calcareous material was derived from sea water by other organisms. 

Since the solidification of the rock much solution and redeposition of 
calcareous matter has taken place. In places the rock contains 
heads of coral replaced by clear, rather coarsely crystalline calcite 
that shows quite plainly the structure of the original head. In 
places the rock is a typical breccia composed of angular and cherty 
fragments in a limy cement, this cement and many of the fragments 
being of a bright red. These breccias evidently represent loose 

1 Dana, J. D., On coral reefs and islands: Am. Jour. Sci., 2d ser., vol. 14, 1852, p. 76, 



GEOLOGY OF SOUTHEEN FLOKIDA. 187 

material that has fallen into solution cavities and been recemented, 
the red color being due to iron oxide. 

The rock is harder within a few feet of its surface than below. 
This is true not only of the ledges which are bare but of those below 
sea level. Besides this general surficial hardening, the rock shows 
in many places on unweathered surfaces a thin layer, generally less 
than 2 inches thick and nowhere, so far as seen, as much as a foot 
thick, that is darker than the rock below and is finely banded. In 
this layer all traces of the corals and shells visible in the mass of the 
rock disappear. The crust follows slight inequalities of surface and 
may represent a deposition of limy ooze in pools or hollows which 
began after the elevation of the reef and in places may be stiU in 
progress. 

Some other features of the rock were brought out by the railway 
work along the keys. Measured in terms of a da3^'s work with a hand 
drill, the rock is twice as hard as the Key West ooHte. Yet, though 
hard, it is so honeycombed with solution passages that many borrow 
pits instead of yielding more loose rock than the cubic contents of 
the pit actually yield less. 

Tliickness, — The only information available regarding possible 
variations in thickness of the Key Largo limestone is that of well 
records. The presence of reef rock below Jackson Square in the city 
of Key West was not shown by the samples of borings described by 
E. O. Hovey,^ but at Key Vaca a well has shown reef rock fully 100 
feet thick. At Indian Key over 130 feet of reef rock is indicated by 
a record published by Hunt, but at Indian Key Channel a weU went 
through hard rock into marl at about 40 feet below sea level. 

PJiysiograpJiic expression. — The causes determining the outline of 
the great arc of the reef have already been discussed. The islands 
form a discontinuous low wall separating the waters of the Atlantic 
from those of Biscayne Bay, the Bay of Florida, and Blackwater and 
Card sounds. Mention has already been made of the average and 
maximum elevation of the rock surface, the depths of the surrounding 
water, the outlines of the keys, and the weathering of the rocks. 

The work of water is shown by the numerous vertical holes forming 
natural wells, or, as they are called, springs, and the many shallow 
hollows or potholes. These potholes seldom reach much below sea 
level. A few holes may run down 20 feet, and free openings or cav- 
ities filled with soft material that extended 30 feet below sea level 
have been noted. Yet, though the rock is full of holes, it is not 
cavernous. Most weUs and potholes end in crevices or passages 
filled with loose material, without free openings of any considerable 

iHovey, E. 0., Notes on the artesian well sunk at Key West, Fla., in 1895: Bxill. Mus. Comp. Zool. 
Harvard Coll., vol. 38, No. 2, 1896, pp. 65-91. 



188 GEOLOGY AND GROUND WATERS OF FLORIDA. 

size. Cavities a foot in diameter extending more than a few feet from 
the bottom of a surface opening are scarce. 

Along beaches the reef rock above mean high-tide mark presents 
a curiously rough and jagged look and is honeycombed with holes 
from the solvent effect of spray. Between tide levels the faces of 
the low ledges are undercut by the waves. In many places a loose 
slab 6 to 12 inches thick and 3 to 6 feet wide looks as though it had 
been thrown up by the sea, or an apparent heavy bedding slopes 
toward the water, giving the appearance of beach rock. Examina- 
tion shows that the loose slab and the apparent bedding are erosion 
effects, due to solution and cementation. The appearance of a spray- 
worn beach is shown in Plate XIV, A (p. 178). 

Paleontologic character. — The Key Largo limestone shows a rather 
small variety of fossils recognizable by the naked eye, though heads 
of corals standing as they grew are numerous, and here and there an 
overturned head hke those of the present reef is visible. All the 
corals are of living species. Determinable shells are not especially 
common, though aggregates of shell fragments are found from place 
to place. Among the most common molluscan remains are the holes 
made by various Hthodomes in the coral. In addition to mollusks, 
foramirdferas, coralHne algse, and echinoids have contributed to the 
formation of the rock. The fossils indicate the post-Pliocene age of 
the reef. 

Areal distribution. — The total length of this Pleistocene coral reef 
is still undetermined. Its essential continuity from Soldier Key to 
Bahia Honda, 90 miles, is undisputed. Virginia Key, north of Soldier 
Key, is covered with sand but is probably underlain by the reef rock. 
The farthest northward growth of Pleistocene reef-building corals 
known is to Hillsboro Inlet, 10 miles north of New River. On the 
east side of the Florida Coast Line canal, south of the inlet, can 
be seen fragments of large heads of reef-building corals (Orbicella, 
Maeandra) that were blasted out in dredging the canal. According 
to Capt. Gleason, who had charge of the dredge, no coral rock was 
found in the work south of this point along the canal. It is possible 
that these heads formed an isolated patch and that the main reef 
never extended so far north. 

Eeef rock is exposed here and there at about low-water mark on 
the south shore of Bahia Honda. To the west it shows on the south 
fat)e of Big Pine Key and on one of the Newfound Harbor keys, 
though obscured in places by angular compactly cemented fragments 
of recent beach rock. It does not show on any of the larger keys 
farther west, though bowlders of coral rock were found, according to 
L. Agassiz, 12 feet below surface at Fort Taylor, Key West. The 
rock is reported on Sand Key south of Key West and probably 
extends under water a considerable distance westward. Thus the 



GEOLOGY OF SOUTHERN FLORIDA. 189 

possible length of the Pleistocene coral reef of southern Florida was 
close to 200 miles. There is no evidence to prove its maximum 
width. The maximum width shown by exposures above sea level 
may be 3 miles. 

The best exposures of the Key Largo limestone are probably those in 
the quarry at Windleys Island, where vertical faces 14 feet high were 
seen. Other good exposures appear in the railroad cuts on Planta- 
tion Key, just east of wSnake Creek, and near the south shore of Lake 
Surprise. The cuts and the many borrow pits show the varying 
structure of the rock and its mode of origin. The bedding that charac- 
terizes most detrital rocks is nowhere visible. The pecuhar features 
of the shore-hne erosion of the rock can be seen at many promontories 
and detached islets along the north side of Key Vaca. 

LOSTMANS RIVER LIMESTONE. 

Synonymy. — ^This term is applied to the nonoolitic fossiliferous 
limestones which apparently underlie the western coast of southern 
Florida and outcrop inland. Though doubtless noted by Army 
officers at the time of the Seminole War, and by other observers since, 
the first published description of these limestones which the writer 
has been able to find is that of Dall,^ who described samples collected 
by Willcox in the winter of 1887-88 at the head of Aliens River 
and in Lostmans River. 

WiUis,^ who subsequently examined the samples, considered that 
certain peculiarities of those from Lostmans River and certain points 
in Dall's description of the location from whence they came, showed 
that the rocks might be in process of formation. 

In this paper all the west-coast nonoolitic Pleistocene limestones 
showing marine fossils are grouped as a single formation although 
they vary considerably in appearance. 

Stratigrapliic position. — ^The Lostmans River limestone underlies 
the gray sands of the mainland, the marls of the coastal swamps, and 
the keys of the southern portion of the Ten Thousand Islands. It 
also extends along the southwestern border of the Everglades. Its 
relations to the nonoolitic marine Palm Beach limestone could not 
be determined in 1908, because the great saw-grass swamp of the 
Everglades separates the nearest natural exposures, the minimum 
interval between outcrops being about 35 miles. The relation to the 
Miami oolite has not been determined with exactness, though from 
samples collected along the Florida East Coast Railway between Long 
Siding and Jewfish Creek the writer believes that the oolite is younger 
than the nonoolitic limestone which lies south of it. Beyond the 

iDall, W. H., and Harris, G. D., Correlation papers— Neocene of North America: BulL U. S. Geol. 
Survey No. 84, 1892, p. 100. 
2 Willis, Bailey, Jour. Geology, vol. 1, 1892, pp. 512, 513. 



190 GEOLOGY AND GEOUND WATEES OF FLOEIDA. 

shore line of the mainland the rock lies below sea level, and its relation 
to the Key West oolite across the Bay of Florida has not been deter- 
mined. 

A well drilled through the rock at Everglade shows that the lime- 
stone there rests on a fine gray sand. It is uncertain whether or not 
the limestone was struck at Marco; possibly it may be represented 
there by unconsolidated quartz sand and shell fragments. 

Lithologic character. — ^The Lostmans River limestone varies so greatly 
that it is impossible to give a description that contains features 
common to all localities. At the type locality on Lostmans River, the 
limestone is described by Dall as very hard rock, consisting of large 
masses of Polyzoa more or less completely changed into crystalline 
limestone. The cavities are filled with crystals of calc spar, hand 
specimens showing individual crystals an inch long. All the samples 
collected by the writer from Lostmans^ River and from below water 
level in Aliens and Turners rivers had common features. Near Deep 
Lake the rock is softer and more friable. Rock from the head of Hen- 
dersons Creek contained much more sand than specimens collected to 
the south; specimens collected at several localities in Whitewater 
Bay from its mouth to its eastern extremity, a distance of nearly 20 
miles show very small proportions of quartz sand; and few micro- 
scopic sections show sand at all. Along the line of the Florida East 
Coast Railway between Jewfish Creek and Manatee the rock is much 
less crystalline than on the west coast or toward the entrance to 
Whitewater Bay. 

Thickness. — The formation is probably thin. The well at Ever- 
glade went through only 30 feet of it, but a well at the plant of the 
Minetto Lumber Co., near the mouth of Shark River, penetrated over 
40 feet of hard rock. 

No wells have been drilled inland through rocks that can as yet be 
correlated with the Lostmans River limestone. The deep wells 
nearest Marco on the east are those on cattle ranges in Ts. 47 and 
48 S., R. 31 E. ■ According to the driller, H. Seniff, of Fort Myers, no 
hard rock was found in these wells near the surface. 

Areal distribution. — Marine limestones have been found to underlie 
the shore of the mainland wherever samples have been collected, 
from Jewfish Creek westward and northwestward to near Marco. 
They outcrop in the southernmost patch of the west-coast pineland 
3 miles northeast of the head of Rock Creek and at the heads of 
Turners and Aliens rivers and Hendersons Creek. 

At Everglade the writer was told that limestones are found nearly 
to the border of the Everglades, 12 miles to the east, and at Hender- 
sons Creek he was informed that outcrops making bare ridges occur 
in the pineland. Limestone is also reported along the road from 
Fort Myers to Fort Shackelford, but the marine origin of exposures 



GEOLOGY OF SOUTHEKN FLOBIDA. 191 

more than 20 miles from the coast of southern Florida has not been 
estabHshed. 

Origin. — ^Willis ^ has suggested that the rock at Lostmans Elver 
was perhaps formed by the deposition of crystallizing calcium car- 
bonate from the presumably limy waters of the Everglades. There 
can be no doubt that deposits of marl are now accumulating along 
the coast, but the present hardening of marl to crystalline limestone 
or the direct deposition of such limestone is not established. As the 
writer has stated, the bedrock of the western coast, wherever sound- 
ings have been made, whether in the Everglades, on swamp islands 
along the coast, or in the numerous creek channels, seems to slope 
gently toward the Gulf. The rock is no farther below water level in 
the swamp than in adjacent channels; moreover, the rock surface in 
channels where the current runs strongly is full of crevices, is 
extremely rough, and is evidently being eroded. Loose fragments 
that have been detached by solution are found not only near the 
mouths of rivers but at their heads, on the bare rock, under marl, 
and under vegetable muck. Another fact that impairs the deposition 
and crystallization theory of Willis is the quality of the Everglades 
water, which, though it contains lime, is far from being as hard as 
the water of most springs and wells in limestone regions. Most of 
the marl in the Ten Thousand Islands has come from the ever-dirty 
shallows of the Gulf and not from the land surface to the east. The 
dark limestones below water in the creeks are the same as those that 
outcrop above water a short distance away, and a recent crystalliza- 
tion from solution of those is hard to understand. 

The limestone on Lostmans Kiver, though containing calcite crys- 
tals an inch long, is not greatly different from other limestones of 
southern Florida. Removal, deposition, and crystallization of car- 
bonate of lime are characteristic of the region. 

The limestone, from its petrographic and paleontologic character- 
istics, is a shoal-water deposit of limy sand and marl, containing 
shells of living species of marine moUusks that have been solidly 
cemented and subjected to conditions favoring crystalline growth. 
In places, no doubt, this growth is still in progress. 

CORRELATION OF PLEISTOCENE FORMATIONS. 

The limestones and the related marls and sands of Pleistocene age 
can not as yet be separated into contemporaneous stages. The best 
that can be done is to group them roughly on the basis of areal extent 
and lithologic resemblance. A careful study of the rocks and asso- 
ciated fossils along the miles of canals now constructed in the Ever- 
glades might enable a more exact differentiation. So far as the 
known facts go, however, the several limestones differentiated by the 

1 Willis, Bailey, Jour. Geology, vol. 1, 1893, pp. 512-514, 
76854°— wsp 319—13 13 



192 GEOLOGY AND GROUND WATEES OF FLORIDA. 

author can not be correlated according to an exact time scale. The 
important fact to be borne in mind is that though they are of Pleisto- 
cene age they are not necessarily contemporaneous, and that though 
the peninsula has grown southward the northernmost exposures of 
the Lostmans River limestone are not necessarily older than the 
southern nor older than the Key Largo limestone. 

LITHOLOGY OF PLEISTOCENE BEDS. 

COQUINA. 

The word coquina is here used, as it is used on the east coast, to 
designate those deposits of cemented-shell fragments and quartz sand 
that can be seen at many localities near the present ocean shore of 
southern Florida. In some exposures noted by the writer the rock 
bore slight resemblance to the long-known occurrences on Anastasia 
Island (PL IX, B, p. 80), being a rather fine grained dense gray sand- 
stone that rang under the hammer. This is probably the rock Gris- 
wold saw inters tratified with coquina (shell rock) near Liaton. 

All phases between shell rock and material made up mostly of 
quartz sand can be found near Hillsboro Inlet, Delray, and Palm 
Beach. At the Spouting Rocks, 4 miles south of Hobe Sound Sta- 
tion, the rock contains quartz grains, coarse and fine, and much-worn 
fragments of shells (including axial pillars of conchs over a foot long), 
the whole so solidly cemented that the seaward face of the ledge, 
worn into shallow grottoes, resists the breakers well enough to make 
a feature of unusual interest, the only spouting horn on the Atlantic 
coast on the United States south of Newport, R,. I. 

Coquina outcrops at Jupiter Inlet, along the east and west shores 
of Lake Worth, at Boca Ratone, at Hillsboro Inlet, and on Sarasota 
Key (PI. X, A, p. 94). It was found in the Florida Coast Line Canal 
at the cut to Indian River, the cut below Hillsboro Inlet, and near 
Boca Ratone. In few places do the ledges make rock knolls, though 
on the island east of Hobe Sound are several knolls, the highest, 
according to Mr. Grant, local representative of the Indian River 
Association, who has surveyed much of the island, having a maxi- 
mum elevation of 30 feet above sea level. Its greatest extent 
inland is undetermined; as exposures seem to be confined to locali- 
ties within a few miles of the beaches, it may be represented inland 
by unconsolidated material. In the canal south of Hillsboro Inlet 
the coquina apparently extended over fossil coral heads. No ledges 
of rock resembling the east coast coquina have been reported from 
the west coast. 

The predominance of weU-worn material in the coquina indicates 
an origin from sands that accumulated on barrier beaches or on 
bars where the surf had full swing. Certain features of the outcrops 



GEOLOGY OF SOUTHEEN FLOEIDA. 193 

east of Hobe Sound suggest that the coquina there has acquired at 
least part of its hardness above sea level. One of the facts testify- 
ing to such consolidation is the presence at the Spouting Rocks of 
numerous vertical tubelike streaks of crystalline calcite which end 
in minute stalactites, indicating a downward movement of lime- 
charged water through passages between sand grains. 

Coquina has been quarried for road metal at several localities 
along the east coast. For this purpose it is not as satisfactory as the 
Miami oolite, for it is not so calcareous, is loosely cemented where 
quarried, and breaks up instead of packing solidly. 



Thq. widespread mantle of sand that is so striking a feature of the 
central part of the peninsula extends as far south as Miami on the 
east coast and south of Everglade on the west coast. The sand is 
composed of angular grains of quartz, varying considerably in size. 
At the surface it is white or gray; below the surface its hue is yellow, 
orange, and red. The color is caused by iron oxide and represents 
the result of subaerial decay, the oxide coming from small grains of 
iron-bearing minerals scattered through the sand. There seems to be 
no sharp dividing line between the gray and the colored sands, the 
intensity of color increasing with depth. The decoloration of the 
surface sands is due to the action of plant roots and of soil bacteria, 
the decay of vegetable matter, and the leaching effect of rains. 

In places there is yellow sand finer and apparently more decayed 
than the bulk of the gray sand; and the sand of the dunes seems to 
be finer and more highly colored than that of the sand plains and 
fiatlands, but there are so many gradations of size and hue that to 
separate the sands into gray and yellow seems a useless undertaking. 

Whence came the sand is an interesting problem. Undoubtedly 
much of it represents the southward invasion of the peninsula by 
material worked down the Atlantic and Gulf coasts by waves and 
currents, the remnant of the material worn by streams from land 
far to the north. Some of it no doubt is all that is left of sandy 
limestones or marls that had accumulated below water level and 
after partial or complete consolidation were elevated and worked 
over or leached, the limy material going away in suspension or 
solution. Possibly some of the sand now lying on the ground in 
southern Florida has been cemented to rock and reduced to separate 
particles many times since the grains were worn from some quartz- 
bearing rock in the hills of Alabama, Georgia, or the Carolinas. 

In journeying dowTi the shores the sands have been moved by the 
wind, blown inland, and the contours of the dunes represent wind 
action, as do to a large extent those of the rolling sand plains. 



194 GEOLOGY AND GROUND WATEES OF FLOEIDA. 



Shell marls having the same general characteristics as those seen 
and described by Mr. Matson at points farther north undoubtedly 
underlie the surface sands at many points in southern Florida. The 
Palm Beach limestone and the Lostmans River limestone undoubt- 
edly here and there grade into such marls, and the Miami oolite con- 
tains lenses of sandy marl. Outcrops of distinctly Pleistocene marls, 
that is, those underlying sands or marls now being worked over on 
flats and beaches, are not common, though found here and there. 
Marls under the sandj^ foreland at Cape Sable are practically con- 
tinuous with those of the prairie at Flamingo. Along the west-coast 
rivers soft marls rise above sea level in the river banks for varying 
distances ; they contain fresh-water shells but are probably contempo- 
raneous with the marls of the Gulf shore, here classed as Recent. 
Near the mouth of Shark River these marls a^re fully 20 feet thick, 
and at the mouth of Lostmans River the strip of marl land is 3 miles 
wide. On many of the keys marls and shell sands form level areas 
having a maximum elevation of possibly 3 feet above mean high tide. 

SUMMARY. 

The summation of the evidence indicates, except along the keys, a 
larger proportion of siliceous material in the early Pleistocene beds 
than in the surficial limestones and less consolidation of sediments. 
Considering the total bulk of the Pleistocene deposits and the relative 
proportion of limy and sandy materials, the facts indicate that on 
the mainland the Pleistocene beds as a whole are not to be grouped 
as limestones. There are limy beds and limestones which can be 
mapped as lithologic units, but the proportion of siliceous and uncon- 
solidated material is much greater than has been supposed. 

THICKNESS OF THE PLEISTOCENE ROCK. 

The maximum thickness of the Pleistocene formations of southern 
Florida can not be determined from the available evidence. There 
was no distinguishable break in deposition, no pronounced change in 
marine life, at the beginning of Pleistocene time. The sequence of 
events shown by the sands, marls, and limestones and the organic 
remains they contain is practically continuous. Pliocene time passed 
and Pleistocene time began with no record of the fact. 

For this reason the total thickness of the Pleistocene formations 
can not be determined from the available evidence. It could be 
approximated with considerable exactness from a study of the fossils 
and a determination of the relative percentages of living and Pliocene 
species found in a given bed, but the drillers of the more important 
wells on the east coast saved few fossils. The evidence, such as it 



GEOLOGY OF SOUTHERN FLORIDA. 195 

is, shows that the Pleistocene beds measure over 75 feet at West 
Palm Beach, over 1 iS feet thick at Delray, over 50 feet at Dania, 
about 90 feet at Indian Key Channel, fully 100 feet at Key Vaca, 
and over 50 feet at Buck Key. Of the above measurements the only 
ones that are at all definite are those at Indian Key Channel and at 
Key Vaca. Fragments of reef-building coral were found at Key 
Vaca at 100 feet. Below was a soft white limestone with shell casts 
that graded downward into a sandy limestone (quartz sands) at 152 
feet; this Hmestone continued to 176 feet and then gave way to a 
clean white quartz sand, the first upper 10 feet of which contained 
many irregular nodules of quartz sand held by a limy cement. The 
changes from quartz sand to sandy limestone at 176 feet, and from 
limestone to undoubted reef rock at about 100 feet, are suggestive 
but insufficient for drawing a sharp line between Pleistocene and 
Pliocene material. It is probably safe to say that below 176 feet is 
Pliocene sand and above 100 feet is Pleistocene reef rock. Though 
the thickness of the reef rock at Key Vaca does not necessarily indi- 
cate the thickness of the Pleistocene beds at Palm Beach or the 
mouth of Caloosahatchee Eiver, 3^et taking all the data into consid- 
eration, the maximum thickness of the Pleistocene of southern 
Florida, disregarding sand hills, is probably about 125 feet. 

RECENT SERIES. 

GENERAL CHARACTER. 

The establishing of sharply marked limits for geologic time intervals 
is difficult, particularly in regions where there are no well-marked 
breaks in the stratigraphic succession nor sudden changes in the char- 
acter of the fossil evidence. Hence differences of opinion may exist 
as to where the line between Recent and Pleistocene time, as applied 
to the geology of southern Florida, should be drawn. The writer, 
however, here includes as Recent all deposits now being laid down or 
that have been laid down sjnce the last weU-marked elevation of 
the land surface. 

Most of the Recent deposits are unconsolidated peats, marls, and 
sands. The consoHdated rocks embrace coquina, a few deposits of 
beach rock of no special importance, some of the calcareous masses 
of corals, coralline algae, shells, and other organic remains now hard- 
ening on the Tortugas ; the growing coral reef outside the keys ; the 
worm rock; and the oyster banks. 



Surficial deposits of peat are found throughout the Everglades 
where saw grass grows tall and in places outside the main body of 
the saw grass. They have resulted from the subaqueous incom- 



196 GEOLOGY AND GKOUND WATERS OF FLORIDA. 

plete decay of roots and blades of saw grass and of other vegetation. 
Their thickness varies greatly. In places they rest on rock; in places, 
especially toward the southern edge of the Everglades, on fine marl; 
over considerable areas, as at New River, they rest on sand. Dredging 
along New River shows one or more peat beds in places, with sand 
beds between. 

The average rapidity with which peat is now accumulating in the 
Everglades is unknown, as is the rate of increase under the most 
favorable or most unfavorable circumstances. Hence the thickness 
of a peat bed at a particular place can not be used as a measure of 
the time that has elapsed since peat formation began there. It is the 
writer's opinion that, because of water level in dry seasons lying 
several feet below surface, and the consequent opportunity for rapid 
decay of vegetable remains, little peat is now accumulating except 
about Lake Okechobee and other lakes and in sloughs. 

MARL. 

Recent marls include beach, swamp, lagoon, and sea-bottom deposits 
of finely divided calcareous material, differing in appearance, origin, 
and manner of deposition. Some represent rock, sheU, or coral 
flour, ground up by the mill of the surf; some, as those accumulating 
in places in the Everglades and in pools along the coast of the main- 
land or the keys, represent lime that had been dissolved and later 
precipitated through the evaporation of the water that held it in 
solution, whereas others, such as the marls accumulating on the bottom 
of Whitewater Bay,^ have been precipitated from solution. Organic 
agencies are undoubtedly active in the work.^ From the first and 
third of these classes of marls have been formed the limy oozes that 
cover wide expanses of the bottom of the Bay of Florida, the inlets 
of the mainland, and the passages about the keys; tidal and wind- 
made currents have heaped them up into flats and banks, and 
through the growth of vegetation they have become islands. Such 
is the history of the gray marls on which flourish the mangrove 
forests of the Shark River archipelago and the Ten Thousand Islands. 

The boundary between limy mud and quartz sand in the southern 
part of the Everglades is said to be along the south line of T. 55, 
Rs. 32 and 33. North of this lime the white marl disappears. 
On the west coast, at Lostmans River, where the Everglades approach 
the Gulf, is a fringe of marl 3 miles wide. 

SAND. 

The sands classified as Recent are those of the shores and those 
that winds and waves move or bury in the work of destruction or 
construction. At Jupiter Inlet and Palm Beach, Hillsboro Inlet, 

1 Second Ann. Rept. Florida Geol. Survey, 1910, p. 228. 

2 Drew, G. H., Year Book Carnegie Inst. Washington No. 10, 1911, pp. 149, 154, 



GEOLOGY OF SOUTHERN FLORIDA. 197 

and even as far south as Cape Florida, the beach material is quartz 
sand with a varying proportion of ground-up sea shells and other 
calcareous material. From Soldier Key around nearly to Cape 
Romano the beaches as a rule are of calcareous sand. Some quartz 
grains, however, appear as far south as the keys; of a series of 47 
samples from the bottom of the inside passages collected between 
Biscayne Bay and Bahia Honda by Vaughan and examined by 
Matson, nearly all show quartz grains, though the grains are fine 
and not particularly abundant west of Card Sound. 

Along the shores of the keys from Soldier Key to Key West the 
beach sand is of corals, coralline algse, Foraminifera, and moUuscan 
shells (single valves of pelecypods and whole shells of gastropods) 
and in many places, as at the sand pits on Lower Metacumbe and 
Long Key, numerous branches of buckhorn coral (Porites). The 
thicker deposits of this sand, 5 to 8 feet at Lower Metacumbe, show 
the material to be roughly stratified, with inconspicuous cross-bed- 
ding; the material includes some fragments of rock a foot long and 
has neither the texture nor the arrangement of a purely eolian 
deposit. The beach ridges near the west end of Long Key, 5 feet 
above mean tide, show that they have reached their present height 
during hurricanes. The work of relatively high waves is particularly 
evident in the outlines of the beach ridges on one of the inner keys — 
Sand Key, off East Cape — which is exposed to seas entering the 
Bay of Florida from the Gulf. 

A striking peculiarity of these calcareous beach sands is their 
slight movement by the wind after the waves have heaped them up. 
Nowhere along the keys has the writer seen the sands moving before 
the wind, as do the siliceous sands on the ocean shore at Palm Beach. 
As Hunt observed, the calcareous sands, once packed, ^'resist the 
blasts of hurricanes and northers." ^ 

CORAL. 

Along the arc of the keys from Soldier Key to the Tortugas, from 
4 to 7 miles offshore, are the growing corals that form the Florida 
reef. This reef is of the barrier type and is separated from the keys 
by a shallow channel, extending from Soldier Key to the Marquesas. 
The reef is terminated by deep water west of the Tortugas. North 
of Biscayne Bay it dies away in scattered clumps and heads as the 
waters become too cool for vigorous growth. Fragments of reef- 
building corals come ashore on the beach opposite Hobe Sound 
station, and similar coral bowlders are said to have been washed 
up by the sea as far north as Canaveral Bight. 

Though of the barrier type, the Florida reef does not rise from 
the sea floor as an almost continuous wall broken by a few narrow 

» Hunt, E. B., Origin, growth, substructure, and chronology of the Florida reef: Am. Jour. Set, 2d ser.j 
VOL 25, 1863, p. 197. 



198 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

openings; rather it comprises heads and patches of coral rising 
irregularly, with many intervals where the bottom is covered by 
calcareous sand and mud. These heads and patches are separated 
by breaks, some several miles long, where corals are few. The 
seaward face of these areas lies along an arc that in a rough way is 
concentric to the arc of the keys and corresponds to the outer edge 
of the old reef. Along it the corals have grown up from depths of 
8 to 10 fathoms. Seaward the bottom falls away and the 100- 
fathom line is within 4 to 10 miles of the line of the outer coral 
patches. Toward the land, in water 5 to 25 feet deep, heads and 
clumps of coral rise to the level of low tide several miles inside the 
arc of the outer patches. 

At a few places along the reef, as at Sombrero Key, on patches 
reaching to tide level, the waves have washed up coral sand and 
bowlders enough to form keys a few rods across, with shifting shore 
lines. Thus the corals build a foundation for dry land, and the 
incipient land growth along the Florida reef led some of those who 
first wrote of the geology of Southern Florida to believe that the keys 
themselves were formed in the same way, without uplift of the 
coast, and that coral reefs had been the principal agency in extending 
the Florida peninsula southward. 

WORM ROCK. 

Aggregations of the limy tubes secreted by a moUusk were seen 
and described by Dall ^ on the west coast. The writer saw many 
such masses. They are particularly noticeable around the shores 
of the outer keys between Cape Komano and Cape Sable. On the 
marly sand flats about Rabbit Key, between tide levels, the limy 
tubes form disconnected masses 2 feet thick and 50 feet wide. 

OYSTER BANKS. 

Banks of solidly packed oyster shells make reefs at the mouths of 
many rivers, particularly on the west coast. Good examples are 
found at Lostmans and Caloosahatchee rivers. 

SOILS. 

The soils of southern Florida differ widely but in general may be 
roughly divided into gray sands, sandy clay, marl, soft rock, and peat. 
The gray sands have been described. Outside the Everglades they 
form the great part of the arable soil. The sandy clays, which are 
mostly sand, underlie many of the prairies in the flatlands. Marl is 
the soil of the mangrove islets and of the islands along the shore of 
the mainland on the south and west. Peat is found in the Everglades 

1 Correlation papers— Neocene: Bull. U. S. Geol. Survey No. 84, 1892, p. 153. 



GEOLOGIC HISTORY. 199 

and in many coastal swamps. '^Soft rock" is the term here applied 
to the partly decayed surface of the Miami and Key West oolites and 
the Key Largo limestone. Trees and shrubs grow from bare sur- 
faces of limestone, orange groves are planted in loose rock, and in 
places the Miami oolite is so soft it can be roughly plowed. 

STRUCTURE. 

The anticlinal structure plainly shown to the north by the distri- 
bution and order of the sedimentary beds that underlie the surface 
sands is not evident in southern Florida, though it is possible that 
an examination of the outcrops in the pinelands south of Caloosa- 
hatchee River may show that a broad low anticline can be traced as 
far as the Big Cypress. 

So far as is now known, however, the rocks that show at the surface 
throughout the south end of the peninsula lie almost flat. Cross- 
bedding with dips as high as 30° may be seen in places; and local 
examples of apparent stratification with lesser dip but greater 
extent are not uncommon; but in general no well-marked evidence 
of regional folding is to be had from a study of rock exposures. 

As the beds lie flat and their elevation above sea level is nowhere 
more than 25 feet and throughout most of the region is less than 15 
feet, it is evident that a thin formation may cover a great extent of 
country and that any tilting or folding of unexposed beds must be 
inferred from what has been determined to the north or established 
through the comparison of carefully kept records of deep borings. 

GEOLOGIC HISTORY. 

By G. 0, Matson and Samuel Sanford. 

DATA. 

The absence of pronounced deformation of the rocks and the low 
relief of the surface of Florida make it difiicult to obtain continuous 
sections of beds. However, by observations of such exposures as 
are available and by the study of samples from wells it has been 
possible to obtain a fairly complete knowledge of the thickness, 
character, and relations of the successive formations from the early 
Oligocene down to the present time. This knowledge permits the 
formulation of a general sedimentary history of the State from the 
deposition of the oldest rocks exposed to the formation of the sand 
dunes and coquina of the present day. 

OLIGOCENE EPOCH. 

Vicksburg epoch. — As a result of the studies already made, certain 
broad generalizations relating to the changes that have taken place 
are possible, one of the most important being that the older rocks 



200 GEOLOGY AND GKOUKD WATERS OF FLORIDA. 

of the State were formed under conditions that were uniform over 
wide areas and that permitted the deposition of several hundred 
feet of homogeneous sediments, whereas the younger formations 
were laid down under conditions that varied greatly within short 
distances and that changed at frequent intervals. That the period 
of deposition of the Vicksburg group was a time of great uniformity 
in conditions over wide areas is well shown by the remarkable 
homogeneity of the beds of this age, which underlie practically the 
entire State. These beds are uniformly fine-grained and show little 
variation in chemical composition. Limestone predominates, but 
sand and clay occur in small quantities, the percentage of these 
impurities being larger in the upper beds. Terrigenous material 
shows an increased percentage toward the northern end of the State, 
where the proximity of older land afforded opportunity for the 
entrance of considerable sand and mud into the Vicksburgian sea. 
Toward the close of this period of deposition a shoaling of the seas 
appears to have permitted the entrance of the fresh-water shells and 
the land-derived sediments noticeable in the Ocala limestone of the 
Vicksburg group. The excellent preservation of many of the shells 
shows that the water must have been comparatively quiet during 
the deposition of the limestone. The inclusion of a small percentage 
of land-derived sediments and in some places of fresh-water shells 
shows that a portion of the limestones of Vicksburg age were prob- 
ably deposited at no great distance from land. Concerning the 
deposition of sediments on the Floridian Plateau Vaughan says : ^ 

The water over this plateau was shallow, probably in no place 100 fathoms deep; 
the bottom temperature was between 70° and 80° F. ; tropical currents passed over 
its surface ; deposits of both terrigenous and organic origin accumulated on it, ranging 
in thickness from 100 to 200 feet near shore to the north to over 1,000 feet near its 
southern margin. As the water was shallow, the sea bottom must have been gradually- 
depressed while the material accumulating on its surface was being deposited. 

The shallow Vicksburgian sea was apparently comparatively free 
from sand and mud and the greater portion of the sediments con- 
sisted of finely divided calcium carbonate containing organic remains . 

In a recent paper Vaughan ^ discusses the precipitation of calcium 
carbonate from sea water. He suggests that the precipitation of 
finely divided calcium carbonate similar to that found in the lime- 
stones of the Vicksburg group may be caused by an increase in the 
alkalinity of the sea water produced by the denitrifying action of 
bacteria: 

The result of Drew's work^ as bearing on the problem of calcium carbonate pre- 
cipitation has been definitely to show that in the tropical waters of the Atlantic 

1 A contribution to the history of the Floridian Plateau: Pub. Carnegie Inst. Washington No. 133, 1910, 
pp. 181-182. 

2 Read before the Geological Society of America, December, 1911, p. 7. 

3 Year Book Carnegie Inst. Washington No. 10, 1911, pp. 149-154. 



GEOLOGIC HIBTOKY. 201 

Ocean denitrifying bacteria by increasing the alkalinity of the sea water cause tur- 
bidity of the water through the formation of calcium carbonate, which is in particles 
80 finely divided that they either will not settle or settle with extreme slowness. 
Drew states that by the use of the centrifuge he was able to cause the precipitation of 
the finely divided material, or by adding finely powdered, hydra ted CaS04 or fine sand 
to such a culture, precipitation is caused by the aggregation of the CaCOg around 
the insoluble particles as nuclei. Mr. Drew sent me a slide of this material pre- 
cipitated in the manner last described, which Dr. F. E. Wright, of the Geophysical 
Laboratory, has examined for me and has submitted a report. The carbonate occurs, 
according to Dr. Wright, in the form of fine radial spherulites, or more rarely as 
individual crystals of rhombohedral outline. The spherulites are only approximately 
round and range in size from minute specks to grains one-tenth of a millimeter in 
diameter. This result bears on the origin of oolites and suggests a method of their 
formation. The activity of denitrifying bacteria, while great in tropical water, is 
much diminished or only slight in temperate or cold water. 

This is the first definitely proven method by which calcium carbonate is chemically 
precipitated in large quantities in oceanic waters. 

Kecent studies of materials obtained by Vaughan from the sea 
bottom among the Florida Keys have shown that they contain a 
large amount of silica. The number of samples collected was 47 and 
more than 250 slides were examined microscopically. In one sample 
which consisted largely of quartz sand no tests of diatoms or spicules 
of sponges were seen, but in the others remains of these organisms 
were numerous. 

The silica which occurred in the fine-grained limestones of Vicks- 
burgian age, being amorphous, was readily dissolved by percolating 
waters and subsequently deposited, replacing the calcium carbonate 
of the limestone. This process appears to have been very active, 
for beds of chert a fraction of an inch to several feet in thickness are 
found to be very persistent at certain horizons ; in fact, it is the chert 
beds that form the confining strata above the artesian water-bearing 
beds. The persistency of these beds may be due to deposition of 
large amounts of silica at certain horizons during sedimentation, but 
it is more probable that the silica was originally distributed through- 
out the limestone and that the chert beds merely represent the 
horizons along which the silica-bearing solutions circulated most 
freely. 

Emergence. — The deposition of the limestones of the Vicksburg 
group was followed by a partial emergence of the land, as had been 
foreshadowed by the increase of terrigenous sediments and the 
appearance of fresh-water shells, which were doubtless washed into 
the sea from adjacent land areas during the deposition of the Ocala 
limestone. The extent of this emergence can only be conjectured, 
but it doubtless affected a considerable area north of Lake Okechobee, 
and it probably extended somewhat beyond the pi-esent boundaries 
of the State. 



202 GEOLOGY AKB GBOUKD WATERS OF FLOBIBA. 

The nature of the movement which closed the period of deposition 
of the Vicksburg group is somewhat obscure, though it was probably 
a continuation of the broad arching of the strata which had been 
initiated during an earlier epoch when the structural basin of the 
Gulf of Mexico was first formed. The irregularity of the surface 
of the rocks belonging to the Vicksburg along the east coast is in 
part due to the deformation which took place at this time and in part 
to subsequent erosion. Following this emergence came a period of 
denudation, when the surface of the land was carved into hills and 
valleys, the evidence of this being found in the uneven surface upon 
which the later beds were deposited. When compared with moun- 
tainous regions the rehef of the surface produced during erosion 
was insignificant, though perhaps comparable with that of the 
same region to-day. 

ApalacMcola epoch. — The erosion interval that followed the deposi- 
tion of the rocks of Vicksburgian age was followed by a period when 
the sea once more encroached upon the land to such an extent that a 
large part of Florida was probably submerged. During this time 
considerable thicknesses of clay, sand, and calcareous mud were laid 
down in the shallow water. In the east-central and south-central 
portions of the peninsula depositions of clay and sand predominated 
during the earUer part of this stage, and farther north and west 
similar deposits characterized its later part. The calcareous mate- 
rials, which are found now in the form of marls and limestones, 
were especially important in the northern part of the State, but they 
were also deposited in smaller quantities farther south. Through- 
out the time represented by the Apalachicola group the conditions 
governing the deposition appear . to have differed considerably in 
neighboring localities, but there was no such abrupt change as may 
be found along the present coast. The changes from sediments of 
one character to those of another were frequently abrupt, and during 
the entire time there was more or less interminghng of different kinds 
of sediments, giving rise to the marls, impure Umestones, shales, and 
sands of this stage. The fuller's earth beds, which occupy consid- 
erable areas in the north-central part of the State, represent short 
intervals of uniform conditions controlling sedimentation, but these 
alternated with conditions permitting the deposition of sands and 
ordinary clays. In general the rocks of the Apalachicola group 
appear to have been marine, but during the latter part of the epoch 
some nonmarine sands were laid down in the Apalachicola Valley. 
During a portion of this time the central portion of the Florida 
Peninsula appears to have been an island separated from the mainland 
to the north by a shallow passage known as the Suwannee Strait,^ 

1 BuU. U. S. Geol. Survey No. 84, 1892, p. 111. 



GEOLOGIC HISTOKY. 203 

but the entire peninsula was probably submerged before the close 
of Apalachicolan time. 

The Hawthorn formation, which is largely clay, appears to have 
been deposited at the southern edge of this strait, whereas farther 
west the deposition consisted of Umestone and marl. The clays 
and fuller's earth of the Alum Bluff and the Chattahoochee forma- 
tions were deposited in this strait. At certain locaHties the condi- 
tions were especially favorable for the development of organic life 
and hence some beds are very fossiliferous, notable examples being 
the '^silex bed" at Tampa and theChipola marl, Oak Grove sand, and 
Shoal River marl members of the Alum Bluff formation. Asso- 
ciated with the other fossils in the ''silex bed" was a large quantity 
of amorphous silica, probably in the form of sponge spicules and tests 
of microscopic plants. Subsequent solution and redeposit of 
this sihca has given rise to the. '^silex." SiUca is also present in 
the hmestones at other localities, especially in the central part of the 
peninsula, but it is much less abundant than in the hmestones of the 
Vicksburg group. Vaughan's summary of conditions of the Floridian 
Plateau at this time is as follows : ^ 

The plateau in early Apalachicolan time had practically the same outline as at 
present; the depth of water north of Tampa was probably in no place over 100 feet. 
Coral reefs were present in southern Georgia across the base of the present peninsula 
and around Tampa ; the temperature was tropical, the minimum for the year being at 
least as high as 70° F. ; the main movement of the ocean water was from the Tropics; 
the sediments consisted to a lesser degree of organic debris and were predominantly 
of terrigenous constituents. 

In the later stage of Apalachicolan sedimentation the dome of Oligocene lying west 
of the present longitudinal axis of the peninsula had by further uplift increased in 
size and was separated from the mainland to the north by the Suwannee Strait. 

There was differential earth movement, the sea bottom being depressed around 
Orange Island and between it and the shore of the mainland to the north, permitting 
additions to the thickness of Apalachicola sediments. During this later stage of the 
Apalachicola the oceanic waters of the region gradually cooled and coral reefs disap- 
peared. The sediments were mostly of terrigenous origin and were laid down in 
shallow water. 

MIOCENE EPOCH. 

PJiysiograpJiic changes. — The period of deposition represented by 
the beds of the Apalachicola group was terminated by an emergence 
of the northern and eastern parts of the State, but deposition may 
have continued on the southern margin of western Florida, where 
some evidence exists of a gradual transition between Ohgocene and 
Miocene beds. The amount of erosion that took place at this time 
can not readily be determined, but the faunal break is so marked 
that it indicates important changes in the physical geography. It 
is not possible to state just how much Florida was directly affected 

1 A contribution to the history of the Floridian Plateau: Pub, Carnegie Inst. Washington No. 133, 
1910, p. 182. 



204 GEOLOGY AND GEOUND WATEKS OF FLOEIDA. 

by the forces which produced the changes then taking place in the 
West Indies and Panama, but its general altitude was probably 
considerably altered. 

Indirectly the elevation of the Isthmus of Panama at the close of 
the OUgocene affected Florida by changing the direction of ocean 
currents and thus producing a marked change in the fauna of the 
Miocene beds. Of the faunal changes at the close of the OUgocene 
Dall says : * 

As indicated by the changes in the fauna, the physical changes attending the close 
of the Oligocene were at first slow, allowing a certain element of transition to appear in 
the Oak Grove or uppermost Oligocene fauna. At the last they appear to have been 
sudden, at least the change in the fauna on the Gulf coast was absolute and complete. 
The change was not only in the species and prevalent genera of the fauna, but a cliange 
from a subtropical to a cool temperate association of animals. Previously, since the 
beginning of the Eocene, on the Gulf coast the assemblage of genera in the successive 
faunas uniformly indicates a warm or subtropical temperature of water, and the sedi- 
ments uniformly show, from the Jacksonian upward, a yellowish tinge due to oxidation. 
In the Oak Grove sands come the first indications of a change toward the gray of the 
Miocene marls. With the incursion of the colder water the change becomes complete. 
Not only do northern animals compose the fauna, but the southern ones are driven out, 
some of them surviving in the Antilles to return later. Some change along the northern 
coast permitted an inshore cold current to penetrate the Gulf, depositing on the floor of 
the shallow Suwannee Strait, separating the island of Florida from the continental 
shore, a thin series of Miocene sediments, which were also carried as far south as Lake 
Worth on the east coast of Florida and Tampa on the west coast, as shown by artesian 
borings. 

At the close of the Ohgocene the State of Florida appears to have had 
the same general form that it now has, though its area was doubtless 
less than it is at the present. With the beginning of the Miocene 
came a submergence that appears to have reduced the land area to a 
narrow strip along the northern end of the State and a peninsula that 
was both shorter and narrower than it is at present. During part of 
this period the central portion of the peninsula may have been 
separated from the mainland by a shallow strait. The exact extent 
of the encroachment of the sea during Miocene times is difficult to 
determine because the deposits have been partly removed by sub- 
sequent erosion and their present extent is in many places obscured 
by younger beds. 

Deposition. — During the deposition of the rocks belonging to the 
Miocene, the conditions in east and west Florida appear to have 
been unUke. In west Florida and as far eastward as the St. Johns 
Valley south of Palatka, the sediments consisted of soft shell marls 
containing a high percentage of sand and clay. The character of the 
materials shows that this marl was a shallow-water deposit which 
accumulated in such close proximity to the shore that a large propor- 
tion of the sediment is of land origin. 

1 Trans. Wagner Free Inst. Sci., vol. 3, pt. 6, 1903, pp. 1549-1550. 



GEOLOGIC HISTOKY. 205 

In the northern part of the St. Johns Valley and extending south- 
ward along the east coast to near Lake Worth the Miocene is repre- 
sented by an accumulation of sand and clay interbedded with more or 
less impure Hmestone. These sediments may have a thickness of nearly 
500 feet at Jacksonville but are thinner toward the south. Limestone 
beds predominate toward the top of this series, but they are also 
found at various other horizons. In the Miocene, as in the preceding 
epoch, considerable amorphous siHca appears to have been deposited. 
This sihca was subsequently redeposited in the form of chert beds 
replacing limestone, and where the original Hmestone was sandy the 
resultant rock resembles a coarse quartzite. The marked thickening 
of these beds toward the north is probably due in part to the prox- 
imity of large land areas to supply the sediments, and in part to 
their deposition upon an uneven surface of the Ohgocene hmestones. 

During this period the Suwannee Strait became closed, and the 
nonmarine sedimentation extended southward over considerable areas 
of OUgocene rocks. These sediments form part of the thick deposits 
of sand and clay extending from the northern boundary of the State 
southward nearly to the outcrops of the Miocene marls. This period 
of deposition was terminated by an emergence that was probably a 
renewal of the same processes of deformation that had been taking 
place since the early Ohgocene. Vaughan ^ has summarized the con- 
ditions during the Miocene with especial reference to ocean currents, 
as follows : 

The plateau had approximately its present outline and thick deposits of arenaceous 
sands were formed practically to its southern limit, certainly as far south as the locality 
of Key Vaca; the sea was shallow, perhaps 25 fathoms is a safe maximum; there was 
depression coincident with deposition on the east coast; the waters were cold, a cold 
inshore countercurrent lowered the temperature to that of the region between Cape 
Hatteras, and Long Island. This southward-moving countercurrent, aided by winds 
and waves, is largely responsible for the greater thickness of sediments on the east than 
on the west coast, and it is the forerunner of the series of countercurrents so important 
in the later history of the region. Toward the close of the Miocene period uplift was 
again initiated, and the Suwannee Strait, should it not have been previously closed, was 
then assuredly above sea level, and the north and south Trail Ridge was formed. The 
uplift seems to have been greater on the east than on the west, for no Miocene is above 
sea level from Levy to Pasco counties on the west coast, while submerged Miocene is 
apparently present off the mouth of Tampa Bay. 

PLIOCENE EPOCH. 

Physiographic changes. — ^The deposition of rocks of Pliocene age 
began with an encroachment of the sea upon the margin of Florida 
until it probably covered all the southern end of the peninsula and 
extended northward beyond the latitude of Lake Okechobee. On the 
east coast the Pliocene sea occupied all the St. Johns River valley and 

1 A contribution to the history of the Floridian Plateau: Pub, Carnegie Inst. Washington No. 133, 1910, 
pp. 182-183. 



206 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

it may also have covered the land east of this river. The present 
margin of western Florida was doubtless submerged, though the part 
extending from Tampa northward nearly to Apalachicola River may 
have been out of water. This is inferred from the fact that the surface 
formations in that region are believed to be Oligocene. However, it 
is possible that the absence of marine Pliocene beds is due to post- 
Pliocene erosion rather than to nondeposition. 

Deposition. — During the Pliocene there was extensive deposition of 
the phosphate gravels known as the Bone Valley gravel ('4and-pebble 
phosphates ")• The conditions which permitted the deposition of this 
gravel appear to have been the low altitude of the land and consequent 
accumulation of products of mature weathering followed by slight 
submergence, which permitted the residual phosphates, sands, and 
clays to be assorted and redeposited by wave action. That there was 
complete weathering of the rocks from which the materials of the 
Bone Valley gravel were derived is shown by the facts that this forma- 
tion contains the comparatively insoluble phosphate of lime, left by 
the solution of the limestones, and that the sands and clays are the 
resultants from the decomposition of other rocks and are not them- 
selves subject to further weathering. The accumulation of such large 
quantities of residual products must have taken place under condi- 
tions that did not permit their ready removal, and such conditions 
would be most likely to be low altitude with abundant heat and 
moisture. 

After the accumulation of the weathered materials a slight sub- 
mergence was necessary to permit their erosion and redeposition in 
their present position. Evidence of the wave action is found in the 
poor assortment of the materials and in the cross-bedding of the sands 
and gravels. A gradual increase in altitude during the deposition of 
the Bone Valley gravel is indicated by the general variation from 
fine material near the base of the formation to coarser material above. 
The Pliocene ocean, according to Vaughan,^ presented some interest- 
ing peculiarities : 

The general outline of the plateau remained as it was in Miocene time; the water 
was shallow, usually between 20 and 30 feet in depth; the temperature was tropical 
in the southern, the Caloosahatchee area; and warm, but slightly cooler, in the north- 
eastern area, in the vicinity of Nashua. The oceanic current over the Pliocene bank 
must have been a warm countercurrent — a, countercurrent because it brought sands 
from the north and deposited them on the Pliocene submarine bank. 

While the Pliocene marine deposition was taking place important lacustrine and 
fluvial deposits were accumulating on the land surface above the sea. 

Pliocene deposition was closed by another uplift of the plateau. Data for a precise 
estimate of the height of the land during this emergence are not available, but the 
evidence obtainable indicates that it was not over 200 or 250 feet as a maximum, and 
as the previous movements of the plateau were differential it is most probable that 

1 Op. cit., p. 183. 



GEOLOGIC HISTORY. 207 

only portions were subjected to oscillations so great. Accompan3dng this oscillation a 

shallow syncline was developed along the axis now occupied by the Kissimmee River, 

with low anticlines on each side. Probably a third anticline was developed west of 

Peace Creek. The axes of these folds are parallel to the longitudinal axis of the 

Peninsula, and have been important in influencing the drainage courses of middle 

Florida. 

PLEISTOCENE EPOCH. 

Uplift — Following the deposition of the Pliocene came an emerg- 
ence of the land that not only included the greater part of the present 
surface of the State but probably also a portion of the area that is 
now submerged. This emergence is regarded as belonging to the 
Pleistocene, though it might with equal propriety be regarded as 
Pliocene. The emergence gave the streams erosive power and caused 
extensive dissection of the Pliocene and older formations. It was 
during this period of erosion that the major features of the present 
topography were produced. Concerning the extent of the emergence, 
there is considerable diversity of opinion, and for this reason the views 
of some of the authors who have discussed the subject will be con- 
sidered. 

A view that has gained some credence is that Florida was at one 
time elevated over 2,000 feet above sea level. Such a Pleistocene 
elevation would have connected Florida with the island of Cuba; but 
in the course of his investigations of the geology of Cuba, Hill ^ found 
no evidence that there had ever been such connection. Moreover, the 
island of Cuba, according to this author,^ has undergone comparatively 
slight changes of level since the beginning of the Pleistocene. It is 
also worthy of note that the geologic history of Cuba has been very 
unlike that of Florida. 

Shaler ^ called attention to the fact that though the sediments of 
northern Florida and the adjacent States are marine they have been 
drained of their original content of salt water to a depth of nearly a 
thousand feet. In a later paper Shaler repeats this statement as 
evidence of recent extensive emergence of the peninsula of Florida, and 
also calls attention to the large submarine springs off the coast. He 
considers that these facts, together with the estuarine character of 
the lower portions of the stream valleys, indicate a subsidence of the 
land since the extensive uplift. That both emergence and subsequent 
submergence have taken place since the late Pliocene will scarcely be 
questioned. The only point in dispute is the magnitude of the 
movements. 

The best known of the submarine springs is situated near St. 
Augustine. According to Capt. E. C. Allen, of that city, the orifice 

1 Hill, R. T., Notes on the geology of Cuba, based upon a reconnaissance made for Alexander Agassiz: 
Bull. Mus. Comp. Zool. Harvard CoU., vol. 16, No. 15, 1890, p. 285. 

2ldem, pp. 243-288. 

3 Shaler, N. S., Note on the value of the saliferous deposits as evidence of former climatic conditionsi 
Proc. Boston Soc. Nat. Hist., vol. 24, 1890, p. 584. 

76854°— wsp 319—13 M 



208 GEOLOGY AND GEOUND WATEES OF FLOEIDA. 

of the spring is about 60 feet across and the depth is about 200 feet. 
The depth of the sea at the point of emergence is said to be about 50 
feet, and the water emerges with enough force to cause a distinct 
convexity of the surface during calm weather. According to some 
authorities it is difficult to row a small boat across the surface above 
the spring on account of the outward movement of the water from 
above the orifice. 

There is no doubt that the marine strata of Florida contained salt 
water at the time of their deposition, and there is good evidence that 
the beds beneath the central part of the State have been drained of 
this water to a depth of several hundred feet. Owing to the fact 
that few deep wells have been cased for more than 200 to 300 feet, it 
is difficult to determine the character of the water from great depths 
because considerable fresh water almost universally enters the well 
near the surface and would serve to dilute any salt water obtained 
from beloWo Moreover, unless the head of the deep supplies was 
greater than that from shallower water-bearing strata, there would 
be a downward movement of the fresh water from the higher to the 
lower beds. However, the apparent absence of salt water in the 
deep wells of the northern part of Florida suggests that their included 
sea water has probably been drained out. The exact depth to which 
this process has extended is somewhat uncertain. Shaler's estimate 
of nearly 1,000 feet is probably too low rather than too high, for in 
a well at Sumterville ^ hard sulphur water was encountered at 1 ,386 
to 1,400 feet, and although the well was continued to a depth of 
nearly 2,000 feet no salt water was reported. The deep wells all 
penetrate limestones of Vicksburg age, and hence it is the beds of 
that age which have been drained of salt water. As a portion of 
these beds have been above sea level since Oligocene time, the salt 
water may have been removed before the Pleistocene. The magni- 
tude of the emergence is not necessarily so great as 1,000 feet, because, 
given the necessary chance for escape, the salt water would probably 
be displaced by fresh water, provided the surface was high enough to 
afford a small hydrostatic pressure. The absence of impervious beds 
of clay above the submarine portion of the Oligocene limestones 
would permit the escape of the water ; and hence a considerable thick- 
ness of the older rocks may have been filled with fresh water without 
being raised much above their present altitude. 

As it is doubtful if the formation of large underground channels 
extends to great depths below sea level, the large springs point to con- 
siderable emergence. This emergence must have been of compara- 
tively recent date, as otherwise the openings would have been choked 
during the deposition of the younger Tertiary formations. These 

1 Fuller, M. L., and Sanford, Samuel, Record of deep-well drillings for 1905: Bull. U. S. Geol. Survey 
No. 298, 1906, p. 198. 



GEOLOGIC HISTOKY. 209 

facts suggest that the channels of the springs were formed during the 
post-Pliocene. It is believed that they date from the uplift which 
permitted the erosion of the deep valleys of the large streams of north- 
ern Florida. 

Concerning the probable changes of level in Florida, Dall says : * 

The on the whole remarkable horizontality of the Floridian strata indicates a free- 
dom from violent changes of level from the time the ''Peninsular" limestone first 
emerged from the sea. Land shells in the Ocala limestone show that then dryland 
existed. South of the Suwannee Strait, closed in late Miocene times, there is no evi- 
dence of subsequent submersion to any serious extent. Two gentle flexures run par- 
allel with the peninsula, having the lake jiistrict between them; a tilting of, at the 
most, 30 feet, up at the east, down at the west, which may have been contemporaneous 
with the flexures; and, for the rest, very slow and slight but probably nearly continu- 
ous elevation never exceeding 100 feet and perhaps less than half that, with dry land 
and fresh-water lakes constantly existing since the Ocala Islands were raised above 
the sea; such is the geological history of the Florida Peninsula. Denudation of the 
organic limestones by solution rather than erosion is the prominent characteristic of 
the changes in the surface. Soft, cruinbling under the finger nail, the rocks of the 
plateau, if lifted 5,000 or 6,000 feet, as claimed by Dr. Spencer, would have been fur- 
rowed by canyons and swept bodily into the sea. Indeed, to me the proposition is 
inconceivable as a fact and incompatible with every geologic and paleontologic fact 
of south Florida which has come to my knowledge. 

The Pliocene beds were laid down when the altitude of the surface 
was low, and the subsequent uplift, to permit the streams to cut their 
valleys to their present depth, amounts to approximately 250 feet 
near the northern line of the State. As the streams appear to have 
cut below the levels of their present flood plains, this estimate may 
be regarded as too low by an amount which, owing to the absence of 
satisfactory data, is yet undetermined but is probably not large. 

Submergence. — The erosion interval which began in the early Pleis- 
tocene or the late Pliocene was succeeded by a slight submergence 
which permitted the sea to cover the southern end of the State 
northward to some distance beyond Kissimmee, though the ridge 
upon which Lakeland is situated remained out of water in the form 
of an island. The St. Johns Valley was also occupied by the sea 
and the land to the east of it may have been again submerged. 
Along the Gulf coast a strip of land of varying width was also covered 
and the sea extended into the valleys of all the large streams, form- 
ing estuaries, which were more extensive than those of the present 
day. 

In his discussion of the Pleistocene submergence Vaughan gives 
a brief summary of the marine conditions : ^ 

The plateau throughout Pleistocene time preserved its general outlines. Shallow- 
water conditions prevailed over its entire submerged portion. In no place were the 

1 Trans. Wagner Free Inst. Sci., vol. 3, pt. 6, 1903, pp. 1545-1546. 

2 A contribution to the history of the Floridian Plateau: Pub. Carnegie Inst. Washington No. 133, 
1910, pp. 183, 184. 



210 GEOLOGY AND GROUND WATERS OF FLORIDA. 

known deposits laid down in water much deeper than 50 feet, and usually from 
barely below sea level to 25 or 30 feet. The temperature north of the latitude of 
the southern end of Lake Okechobee was slightly cooler than in Pliocene time, but 
it was still warm. In this shallow warm sea sediments of diverse kinds were depos- 
ited. Sands and shell marls are probably the most extensive, forming widespread 
deposits over almost the entire submarine bank. The sands extend beneath the lime- 
stone formations as far south as Miami and perhaps to the southern keys. Along 
the more northerly portions of the bank coquina accumulated. Along a curve, first 
southward and then bending westward, from Biscayne Bay, a coral reef flourished, 
separated by a channel of deeper water from the main bank, on which the Miami oolite 
was forming or had formed in shoal water, strongly agitated by currents. Along the 
southwestern portion of this bank, also in shoal water, the Lostmans River limestone 
accumulated. West of the coral reef, on an extensive flat in the shoal water over 
them, the Key West oolite was formed. Toward the close of the Pleistocene the 
previously formed sands, marls, and limestone southward beyond Miami received 
a thin coating of siliceous sand. Contemporaneous with this purely marine work, 
the terracing of rivers to the north was taking place. 

Pleistocene time was closed by an uplift, which may have been intermittent or 
may have been accompanied by oscillations. There is some evidence of slight depres- 
sion since the principal uplift. After this uplift the living coral reefs developed, the 
Everglades were formed, and the Florida of to-day was the result. 

Terraces.— Durmg the interval of extensive Pleistocene erosion 
the so-called Lafayette upland had been considerably dissected and 
its materials had been deposited in the valleys which were being 
excavated. Before the beginning of the cycle of submergence there 
was a large addition to the detrital surface materials in the form of 
coarse-grained sand that had accumulated as a result of weathering. 
The geographic extent of the submergence was extensive, for t 
probably covered the major portion of the State below the 100-foot 
contour and possibly a somewhat greater area. The submergence 
permitted the waves of the Pleistocene sea to erode and redeposit 
the weathered materials that had accumulated on the surface, and 
in places unweathered portions of the older formations were reworked 
by the sea. The principal effect of the Pleistocene wave action was 
to cut away portions of the hills and to deposit the detritus in the 
depressions, thus producing a moderately level plain. The inner 
margin of this plain is marked by a low scarp and the outer edge 
descends by a similar scarp to the next lower plain. 

Subsequent to the formation of the upper terrace two similar 
plains — the Tsala Apopka and the Pensacola terraces — have been 
formed at successively lower levels. The description and distribu- 
tion of these terraces have been outlined in discussing the physio- 
graphic history of the State. 

The Pleistocene terraces (pp. 31-35) were formed during compara- 
tively late Pleistocene time. There is abundant evidence of a long 
interval of erosion preceding the formation of the oldest terrace, 
and the latter, where traced westward, is found to be as late in 
deposition as the main body of the loess of the Mississippi Valley. 



GEOLOGIC HISTORY. 211 

There is still some doubt as to the relations of the loess and the 
uppermost Pleistocene terrace, but all the evidence so far obtained 
indicates that if the two were not deposited coincidently the loess 
deposition preceded the terrace formation. If the main body of the 
loess is correlated with the closing stages of the invasion of the lowan 
ice sheet into the northern portion of the United States the ter- 
racing must be largely post-Iowan. 

There is a lack of information concerning the details of the late 
Pleistocene history. Shattuck, in discussing the Pleistocene of Mary- 
land, separates the successive terraces by intervals of elevation and 
erosion.^ The rarity of good exposures in Florida, together with 
the general nature of the investigations, make it difficult to form an 
opinion on the exact sequence of events. As an alternative theory 
the formation of the terraces has been regarded as an episode in the 
emergence of the land after its maximum submergence. The ero- 
sion interval preceding the submergence is well established and the 
irregular surface produced by erosion is only imperfectly masked by 
the deposits of the oldest Pleistocene terrace. Erosion since the for- 
mation of the terraces is also evident and a Recent depression has 
transformed the lower ends of the valleys into estuaries; but of the 
physiographic history between the time of the formation of the 
highest and lowest terraces it is not possible to draw conclusions 
from observations in Florida. 

Southern Florida. — Southern Florida presents conditions that do 
not permit differentiation of all the different Pleistocene terraces. In 
fact, only the Recent and the lowermost portion of the Pensacola ter- 
races are represented in that area. However, the various Pleistocene 
formations probably include representatives of deposits made during 
the deposition of the uppermost portion of the Pensacola terrace and 
of the two older terraces. The earth movements indicated by condi- 
tions in southern Florida are a depression, probably the one initiating 
the formation of the Pleistocene terrace; an uplift, doubtless the one 
that closed the deposition of the Pensacola terrace materials; and a 
subsequent depression that permitted the submergence of a portion of 
the coastal lowland. 

Though the Pleistocene limestone formations of southern Florida 
that have been described (pp. 175-191) apparently extend under wide 
areas, all except the Key Largo limestone are rather thin. They 
grow sandy toward the north, where they rest on less consolidated 
material or on formations containiag sandy beds and are more or less 
covered by sand and marl. 

At some places along the east coast well records show considerable 
thicknesses of coquina and beds of well-worn quartz sand and shell 
fragments; at others they reveal relatively thin beds of limestone 

1 Shattuck, G. B., Pliocene and Pleistocene: Maryland Geol. Survey, 1906, p. 137. 



212 GEOLOGY AKD GROUND WATERS OE FLORIDA. 

with sands and gravels above and below. Along the east coast and 
on the keys are rock outcrops 15 feet or more above tide; along the 
west coast are none. The surface sands in some places form long, low 
ridges and in other places mounds 60 feet high. Many of these sand 
ridges rise from ground where growth by wind action is now impos- 
sible. 

From the conditions thus summarized may be inferred a period of 
submarine upbuilding by quartz sands and limy material, which was 
moved southward by currents, and a period of gentle depression, of 
possibly 100 feet, during which beach or bar deposits thickened on the 
east coast, the coral reef grew and spread south of the mainland, and 
quartz sands and limy sands and muds accumulated in wide expanses 
of shallow water behind the bars and the reef on the west coast. 
There is no evidence in the fossil remains that the climate or the ocean 
water was colder than at present. In fact the growth of large heads 
of reef -building corals as far north as Hillsboro Inlet indicates warmer 
water. 

Following this depression came an uplift of the land, perhaps of 
100 feet, or perhaps more, above its present level. Beach sands, 
driven inland, formed dunes. The limestones were eroded by the sea 
and honeycombed by the downward movement of surface waters. 
Following this uplift came a slight depression, bringing the land to its 
present level. 

These are the broader features of the changes indicated in Pleisto- 
cene time, but it is probable that neither depression nor uplift was 
uniform; there may have been pauses or even comparatively brief 
reversals of swing (certain features of the keys and their shores suggest 
more than one elevation above sea level), but nowhere is there indi- 
cation of a great uplift. 

RECENT EPOCH. 

Northern and central Florida. — The slight submergence which has 
taken place in northern and central Florida in comparatively recent 
times has permitted the sea to enter the lower portions of the stream 
valleys and has covered a narrow belt of land along the entire coast. 
The small submerged valleys along the west coast were doubtless 
carved during the uplift just preceding this last submergence. That 
the movements which have taken place have not always affected the 
entire State uniformly appears probable, and this recent submergence 
of valleys on the west coast has been regarded as an example of 
unequal movement. The following statement by Dall ^ illustrates 
one of the views which has gained wide credence : 

The mapping out of the distribution of the different geological horizons from many- 
isolated observations, * * * taken into consideration with the observations of 

1 Trans. Wagner Free Inst. Sci., vol. 3, pt. 6, 1903, p. 1544. 



GEOLOGIC HISTOEY. 213 

Shaler and others on the east coast, indicated that the peninsula of Florida has expe- 
rienced a tilting by which the eastern margin has been elevated between 20 and 30 
feet, while the western coast has been depressed about the same amount. This tilt- 
ing is supposed to have taken place since the Pliocene. To the data of 1891, upon 
which the above generalization was based, Mr. Willcox has lately added observations 
which still further emphasize the fact. He finds that, of the streams falling into the 
Gulf of Mexico from the peninsula in the relatively shallow waters over the submerged 
plateau to the west, channels cut in the limestone may be traced for some distance. 
As these channels, too small to make any marked feature on the usual hydrographic 
chart, could not have been cut since the sea has covered the plateau, the inference is 
obvious that they were cut before the tilting of the peninsula," when the limestone was 
above the level of the sea. 

The drowning of the St. Johns River valley, which permitted 
brackish water to extend far inland, beyond Jacksonville, shows that 
the east coast as well as the west has recently been depressed. The 
amount in either case was probably comparatively shght, though it 
is difficult to obtain precise data. However, as the channel of 
St. Johns River is at least 65 feet below sea level opposite Jackson- 
ville, it is safe to assume a depression amounting to over 50 feet. An 
equal amount of submergence is suggested by the depth of water 
covering the submarine spring near St. Augustine, and a far greater 
depression is suggested by the depth of this spring, which, as already 
noted, is reported to be 200 feet; but this greater submergence prob- 
ably took place before the deposition of the Pleistocene sands and 
marls. 

Earth movements are doubtless taking place along the coast of 
Florida at the present time, but the rate of change is so slow that it is 
only under the most favorable conditions that the effects of the 
movements are noted. One of the earliest recorded observations on 
coastal changes was made by Gorrie ^ in 1854. According to this 
writer the coast at Apalachicola was gradually sinking during the 20 
years preceding 1854. The evidence upon which the conclusions 
were based was the increased depth of water on the bar at the South 
Pass to Apalachicola Bay; the submergence of tree trunks and roots; 
and permanent submergence of oyster reefs that were formerly 
exposed at every low tide. The increase in depth of water over the 
bar at the entrance of the harbor might be accounted for by the 
action of waves and currents. If the water of the bay was prevented 
from escaping readily it is possible that the water level might have 
been raised slightly, but the deepening of the pass across the bar 
should have furnished a free passage for the water, and. hence the 
submergence of trees and oyster reefs was probably due to an actual 
change in the level of either land or water. The amount of sub- 
mergence was estimated at 8 or 9 inches in 20 years, or approxi- 
mately 7 feet per century. 

1 Proc. Boston Soc, Nat. Hist., vol. 4, 1854, pp. 391-392. 



214 GEOLOGY AND GKOUitI) WATERS OF ELOEIDA. 

In 1902, Vaughan * obtained information which indicates that the 
coast in the vicinity of St. Marks has been rising within the last half 
century. The evidence shows that a Httle pond which was formerly 
overflowed at high tide is now entirely drained and is not invaded 
by the sea except by a high tide coupled with a strong onshore wind 
that has been blowing for at least two days. The ordinary high tide 
is said to fall 300 yards short of reaching the pond, in spite of the fact 
that the connection with the sea is less obstructed than formerly. 
This change, which is estimated at 1 to IJ feet since the fifties, 
is thought to indicate an emergence of the land at the rate of 2 to 3 
feet per century. 

These two cases indicate two opposite movements within a short 
distance of each other. At Apalachicola the observations cover 
about 20 years prior to 1854 and at St. Marks they cover the last half 
of the century. If the observations recorded should be given full 
credence, there would still remain a question as to whether there 
was a change in the direction of movement about the middle of the 
century or whether there are two opposite movements on the same 
coast. 

The only record of recent movements on the east coast is contained 
in a brief note by Lewis,^ who reports the submergence of stumps of 
cedar trees at St. Augustine. The amount of the movement is not 
recorded. 

Southern Florida. — Although the accumulated evidence shows that 
the Pleistocene and Recent history of Florida has been marked by no 
great disturbances, that the elevations or depressions of the land, 
though affecting great areas, have been relatively small in amount, 
and although there is no reason to suppose that the region will be 
violently disturbed in the immediate future, yet as the question of 
relative permanency of height of land is of importance because slight 
changes with respect to sea level will have a pronounced effect on the 
habitability of the coasts, the evidence available is briefly summarized. 

That the coast line has been elevated the old coral reef of the 
Florida keys is abundant proof. That it has been slightly depressed 
since the maximum elevation is indicated by solution cavities in the 
limestones extending considerably below present water level and by 
the relation of the dunes to present shore lines. 

As to more recent changes and the present movement the evidence 
of swamps, of shore lines, and of human records may be adduced. If 
the swamps are being depressed there should be tree trunks of the 
older forests buried beneath the sediments that have accumulated 

1 Evidence of recent elevation of Gulf coast along the western extension of Florida: Science, new ser., 
No. 404, vol. 16, 1902, p. 514. 

2 Lewis, E., Evidence of a probable modern change of level on the coast of Florida: Am. Jom-. Sci., 
2d ser., vol. 41, 1866, p. 406. 



GEOLOGIC HISTOBY. 215 

since the trees fell. The writer noted a thick stump in gray marl at 
one of the numerous entrances to Shark River, near the plant of the 
Minetto Lumber Co. It was about 3 feet below the present surface 
of an islet, which is covered by water at high tide. The evidence was 
not conclusive, as the stump might not have been where it grew. 
Still the present growth of the swamps favors a recent depression, 
as does the existence of mangrove swamps about the bases of sand 
dunes near the coast. The dunes evidently are younger than the 
Pleistocene limestones they overlie and in age are probably late 
Pleistocene. A depression of at least 10 feet between late Pleistocene 
and present time is indicated by the swamps fringing many dunes. 

The testimony of the shore lines is contradictory. Possibly the 
best evidence is that of the series of low beach ridges extending from 
East Cape to North Cape on Cape Sable. This strip of foreland, 
having a steep beach of coarse shell sand facing the Gulf and falling 
off inland to a mangrove swamp flooded at spring tides, seems to show 
that there has been a slight sinking of the coast since waves 
started to heap up the sand. Other evidence of depression is found 
along the keys. At several places along the right of way of the 
Florida East Coast Railway peat beds, evidently representing former 
mangrove swamps, were found covered with beach rock or marl 
below tide level. 

The human records to which appeal can be made are the numerous 
Indian mounds, or kitchen middens, composed chiefly of oyster 
shells, found at many places along the coast. (See p. 162.) Some 
of the mounds are of great size, notably the accumulation of shells on 
Chokoluskee Island, which covers nearly 100 acres to an average depth 
of 5 feet. Since the mounds stand in swamps the relation of the bot- 
tom layers of shells to present sea level and to the deposition of marl 
and vegetable matter in the surrounding swamps should be an index 
of any coastal rise or fall. An examination of mounds at Jupiter 
Inlet, in and near Chokoluskee Bay, and at Marco, however, gave fewer 
data than were anticipated. In places creek channels have cut into 
the mounds, in places wells have been sunk through them; conse- 
quently sections showing relations of the lowest layers of shells to 
sea level and to the underlying materials are not hard to find. The 
sections show that around the edges of the mounds there has been 
some burying of shells by wash, but the bottom layers rest on peat 
and marl at about low- water mark; so if the first Indian dwellings 
stood on posts in ground flooded at high tide, there is no sign of a 
measurable sinking of the coast since the time when the building of 
the mounds began. 

Thus the evidence at hand shows that the coast of this part of 
Florida is not now rising but is stationary or sinking. If it is sinking, 
then the rate of depression is so slow that it can not be determined 



216 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

from human records which must antedate the discovery of America. 
A depression of the coast in Recent time is, however, beyond doubt. 

TopograpTiic changes. — ^The Recent geologic and topographic changes 
of importance in northern Florida consist of the deposition of coquina, 
sand, marl, peat, and muck and the formation of sand dunes and 
ridges. Rapid deposition of sand and coquina is taking place along 
both the Atlantic and Gulf coasts, and more or less marl and partly 
decomposed organic matter in the form of peat and muck is being 
deposited in the marshes and lagoons. The formation of dunes and 
ridges of sand is especially active along the east coast as far south as 
Hobe Sound, and a similar action, on a much smaller scale, is taking 
place in the interior of the State. Solution and the consequent forma- 
tion of underground channels, sink holes, and natural bridges doubt- 
less began with the emergence of the calcareous rocks and is still 
going on. The effects of solution are shown by the emergence of 
water bearing mineral matter in solution and by the occasional sub- 
sidence of small areas. 

In southern Florida in Recent time the Everglades formed to the 
south of a lake larger than the present Lake Okechobee. Sands and 
marls from the waste of the land and the ground-up remains of 
marine organisms and calcium carbonate precipitated from sea water 
were deposited along the shores of the mainland and keys. Pine 
forests covered the sand hills and the topography of the mainland 
assumed its present aspect. Near the Gulf Stream corals built the 
modern reef. Waves and currents shaped marls and sands into the 
atoll-like group of the Marquesas and piled up coarser materials to 
form the Tortugas. 

The surficial limestones of southern Florida are, as a rule, soft and 
porous and are remarkably free from aluminous material; hence, they 
are easily disrupted by tree roots, readily dissolved by percolating 
surface water charged with carbon dioxide, and eroded without diffi- 
culty by waves and streams. The effects of solution are everywhere 
visible in the outcrops of oolite and coral rock; the potholes, natural 
wells, and springs show how active has been the work of underground 
water. The jagged surface of the Miami oolite (see pp. 177-180) and 
the bareness of its ridges show how easily it dissolves and how free 
the original sediments were from clay. 

Along the coast, wherever rocks reach the water edge, the waves 
are eating them away. Tidal and wind-made currents carry off part 
of the waste in solution and part in suspension, and distribute the 
coarser detritus as sand. 

Besides the currents and waves which assort, distribute, and pile 
up the waste of the land, organic agencies play an important part in 
extending the shore lines. In fact such agencies are of greater 
importance in south Florida than in any other part of the United 



I 



GEOLOGIC HISTORY. 217 

States, for here coral polyps are building up rocklike ledges strong 
enough to stand, for awhile at least, the hammer of the breakers, 
and mangroves are arresting and holding finely divided material 
that had been swept about by currents. In addition, thick beds of 
oyster shells form banks, hard masses of ^'worm rock" (limy tubes 
secreted by moUusks, see p. 156) protect and extend shore lines, and 
perhaps most important of all the remains of the teeming vegetable 
and animal life of the salt water contribute in the aggregate an 
immense amount of material to the upbuilding of the land. 

The lagoons or '^rivers" of salt or brackish water back of the 
beaches are being filled by swamp growths. Although the tidal 
swiag is small, the extent of the lagoons and the volume of water 
discharged at each ebb is sufficient to transport and assort lighter 
debris, but in the shaping of the coast the waves and alongshore 
currents play the chief part. 

In the Bay of Florida, though the rocky shores of the coral islands 
show the rip of the sea, banks and marl flats are gaining and man- 
groves are vigorously extending the land. Tidal currents are the pria- 
cipal agencies of transportation along the south side of the bay, where 
under favoring conditions currents with velocities as high as 5 miles 
an hour rush through the openings between the keys. Along the 
north side of the bay tidal action is much weaker and winds and cur- 
rents perform a proportionately larger part of the work. Wave 
action, though important, is limited by the shallowness of the bay. 

From East Cape to North Cape a strip of shell sands, the Cape 
Sable foreland, has been pushed up from the bottom by the waves. 
Tidal action is strong; there is a pronounced tide rip past Middle 
Cape, though there is no dominant alongshore movement of sand 
north or south. From North Cape to Cape Komano stretches of 
beach are few; mangroves grow out of the water of the Gulf, and 
the shore line is extremely intricate. Tidal scour is strong at the 
inlets leading into Whitewater Bay, but to the north most of the 
entrances are obstructed by bars. From Cape Romano to the mouth 
of Caloosahatchee River the shore-line topography resembles that 
of the east coast. Lorfg beaches of sand, spits, and bay bars denote 
adolescence. The predomiaant movement of sand alongshore, as 
shown by offsets and overlaps, is southward. This indicated south- 
ward drift is probably due to the effective onshore winds from the 
west and northwest rather than to a prevailing easterly movement 
of air currents. The great seas of hurricanes and northers are of 
chief importance in distributing and piling up the sands. 

To the interplay of these agencies of waste and growth are due 
the peculiar features of the shore-line topography. The importance 
of these features has often been noted, but most accounts of the 
geology of the region have failed to discriminate sharply between the 



218 GEOLOGY AND GEOUKD WATERS OF FLORIDA. 

agencies that wear away the land and those that extend it; or have 
given undue importance to one cause in comparison with the others. 
As an instance may be cited the southern growth of the mainland 
and the character of the mangrove islands along the northern part 
of the Bay of Florida and in Blackwater and Card sounds. The 
bedrock floor of limestone that outcrops in the Biscayne piaeland, 
on Long Key, and adjoining keys in the Everglades, slopes gently to 
the south. On it the marls below the sandy beaches of Cape Sable, 
the marls of the prairie back of Flamingo, and the marls of the great 
mangrove swamp to the east and of the mangrove islands in the 
bay, have accumulated. Hence these islands and the projectiQg 
tongues of swamp along Blackwater Sound can hardly be, as some 
observers have held, erosion remnants of a formerly continuous land 
surface. Eather do they represent the work of agencies, which, if 
unchecked by a depression of the coast, will ultimately join the 
mainland to the keys. 



PART III.— UNDERGROUND WATER. 
GENERAL. FEATURES. 

By G. C. Matson. 
SOURCE. 

The immediate source of potable water is the moisture precipitated 
from the atmosphere in the form of rain, dew, and snow. Of these, 
the last is important in Florida only at long intervals when an excep- 
tionally cold season causes considerable snowfall near the northern 
boundary of the State. By far the most important source of potable 
underground water is the rainfall; but a considerable amount is con- 
tributed by the lower layers of the moisture-laden atmosphere when 
it comes in contact with the cool surface of the ground or enters the 
pores of the soil and is there cooled below the dew point. 

As rainfall is the most important source of the underground 
water it is necessary to consider the amount of the precipitation in 
that form. In a large State like Florida it is difficult to estimate 
the average precipitation because conditions vary in different parts 
of its area. This variation is well shown by the average annual 
rainfall at the following localities : ^ 

Rainfall at localities in Florida. 

Inches. 

Jacksonville 53. 21 

Jupiter 59. 19 

Key West 37. 57 

Tampa 53. 99 

Pensacola 56. 33 

A comparison of the rainfall at these localities is not wholly satis- 
factory because no two amounts represent averages for the same 
number of years. All the records end with 1904, but each began 
at a different date, going back 33 years at Jacksonville, 17 at Jupiter, 
34 at Key West, 5 at Tampa, and 25 at Pensacola. 

If allowance be made for the fact that Key West lies some distance 
off the coast, where the conditions differ considerably from those of 
the mainland, it will be possible to form some idea of the average 
precipitation, and when all the factors are taken into account it seems 
safe to place it at about 52 inches for the entire State north of the 

1 Computed from report of W. B, Stockman, United States Weather Btireau, 1904. 

219 



220 GEOLOGY AND GEOUND WATEKS OF FLOKIDA. 

keys. This does not mean that the rainfall of any particular year 
may not diif er widely from this estimate ; in Florida, as elsewhere, 
some years are exceptionally dry and in others precipitation is 
excessive. 

The water which falls upon the surface is disposed of in three 
ways — by evaporation, by direct run-off, and by absorption. The 
amount which evaporates before it enters some of the drainage chan- 
nels or is absorbed by the soil is so small that direct evaporation is 
unimportant. 

The amount of water which escapes over the surface depends upon 
several factors, such as the rate of precipitation, the topography, and 
the texture of the surface and subsurface materials. Other things 
being equal, a slow precipitation upon a flat surface covered with porous 
soil, which, in turn, rests on porous rocks, will insure the maximum 
absorption, and, conversely, will permit the least possible amount of 
surface rn-off. Probably no part of the country presents less 
favorable conditions for the escape of water over the surface than 
Florida, where the land is almost everywhere flat or gently roUing 
and is covered with a mantle of porous sand, which in turn rests 
on very porous limestone. Locally, of course, conditions may favor 
immediate run-off, as in some parts of the peninsula and over con- 
siderable areas in the northern and western portions of the State 
where the subsurface beds are of clay. Moreover, the limestones 
are not everywhere porous, and in some localities they contain accu- 
mulations of more or less impervious materials, such as dense marls 
and chert, which may act as obstacles to the downward movement 
of the ground waters and hence lead to early saturation of the surface 
beds, a condition naturally followed by the movement of water 
directly into surface streams and ponds. Locally, also, the surface is 
formed into depressions known as sink holes, which receive a large 
amount of water and convey it to underground drainage channels, thus 
lessening the amount of surface drainage. However, the local char- 
acter of these obstructions prevents their greatly affecting the average 
absorption for the entire State, and it appears safe to estimate the 
direct run-off as low as about 2 inches per annum, or 4 per cent of 
the rainfall. This estimate should not be confounded with results 
determined by gaging streams, for in streams the measurements 
show not only the direct run-off, but in addition a much larger quan- 
tity of water which was first absorbed by the rocks and later returned 
to the surface by springs and seepage. It will thus be seen that the 
amount of underground water is greatly augmented each year. It 
might also be inferred that the amount of underground water is large, 
and this is true ; nevertheless, the supply is by no means inexhaustible. 



UNDERGKOUND WATER. 221 

AMOUNT OF UNDERGROUND WATER. 

IN THE EARTH AS A WHOLE. 

Considerable quantities of water occur in cavities and crevices in 
rocks, but by far the larger proportion occurs in the minute pores 
between the individual grains of porous rocks. The earth's crust is 
under enormous pressure at no great depth from the surface, and it 
has been estimated that at a depth of approximately 6 miles this 
pressure must be sufficient to close all openings. Numerous attempts 
have been made to estimate the amount of water contained in this 
comparatively thin outer zone, and conclusions have been reached 
which, though not susceptible of verification, are of sufficient interest 
to warrant recapitulation. 

One of the earliest estimates of the quantity of water in the earth's 
crust is that of Delesse,^ who considered the amount sufficient to form 
a sheet of water on the surface of the earth more than 7,500 feet thick. 
Later estimates have been more conservative, but some of them are 
large. Th^ most important are those of Slichter,^ who figured the 
depth of the sheet of water at 3,000 to 3,500 feet; Chamberlin and 
Salisbury ,3 who put it at 800 to 1,600 feet; Van Hise,* at 226 feet; 
and Fuller,^ at 96 feet. 

AMOUNT OF UNDERGROUND WATER IN FLORIDA. 

In attempting to apply these estimates to Florida, it was found 
that though the data for exact determination were wanting the 
amount of underground water was evidently greater than the average 
given by either Van Hise or Fuller. The thickness of the sands and 
porous limestones in Florida is known to exceed 1,200 feet, and, 
assuming an average porosity of 20 per cent of their volume, these 
rocks would contain enough water to cover the entire surface of the 
State to a depth of more than 240 feet. This estimate should not 
be taken as a measure of the amount of potable water, because the 
deeper waters of Florida are too highly mineralized to be classed as 
such. 

The amount of underground water in Florida has been determined 
by assuming an average porosity of 20 per cent and considering the 
known thickness of the water-bearing sediments. This gives an 
amount which, though large, is probably very much below the actual 
quantity of water which lies below the surface of the State. How- 
ever, from the standpoint of the consumer, this amount is far too 

1 Delesse, Achille, Bull. Soc. g6ol. France, 2d ser., vol. 19, 1861, p. 64. 

2 Slichter, C. S., Motions of underground waters: Water-Supply Paper U, S. Geol. Survey No. 67, 1902, 
p. 14. 

3 Chamberlin, T. C, and Salisbury, R. D., Geology, vol. 1, 1904, pp. 206, 207. 

* Van Hise, C. R., A treatise on metamorphism: Mon. U. S. Geol. Survey, vol. 47, 1904, pp. 128-129. 
6 Fuller, M. L., Total amount of free water in the earth's crust: Water-Supply Paper U. S. Geol. Survey 
No. 160, p. 72. 



222 



GEOLOGY AND GEOUKD WATERS OF FLORIDA. 



large, because the greater part of the supply is too saline to be of 
value. The thickness of the sediments containing potable water 
varies from practically zero on the keys to over 1,000 feet in the 
north-central part of the peninsula, and the average thickness is 
thought to be about 500 feet. Since only the surface waters in the 
southern part of the peninsula are sujQ&ciently free from salt and 
other objectionable mineral matter to be classed as potable, this 
estimate may be regarded as generous. If the rocks which contain 
potable water are assumed to have a porosity of 20 per cent, the 
amount would be sufficient to cover the entire surface of the State 
to a depth of only 100 feet. 

EVAPORATION OF UNDERGROUND WATER. 

Most of the water which is absorbed by the soil is either lost to the 
air by evaporation or returned to the surface by means of springs 
and seeps. 

Evaporation takes place directly to the air, which enters the pores 
of the soil and passes downward to the saturated or partly saturated 
beds; but the circulation of air through the soil is so slow that the 
amount of water lost in this maimer is seldom important. A much 
larger quantity of water is lost by evaporation from the surface 
layers of the soil, the capillary movement of water from the lower to 
higher layers constantly renewing the supply at the top. The loss 
of water in this manner is influenced by temperature, humidity, and 
the texture of the surface layers; and consequently quantitative 
estimates are uncertain. The figures given below are taken from a 
table by King,^ and are intended to illustrate the effect of keeping 
the surface layers loose to a depth of 3 inches. King's experiments 
were made in North Carolina, but soils of similar character to those 
he examined are widely distributed in Florida. 

The table given below shows the evaporation from the surfaces 
during 28 days, from July 17 to August 14, 1902, inclusive. 

Evaporation from soils of different types. 
[In inches.] 





Type of soil. 


Surface condition. 


Sand 
hill. 


Norfolk 
sandy 
loam. 


Norfolk ' 

fine 

sandy , 
loam. 


Surface firm 


1.880 
.205 


4.170 
.770 


6. 51S 


Surface loose for 3 inches^ 


1.135 







These results are not susceptible of close application because oi 
the great difference between the amount of evaporation from loos( 

1 King, F. H., Some results of investigation in soil management: Yearbook U. S. Dept. Agr., 1903, p. 159. 



UITDERGROUND WATER. 223 

soil and soil with compact surface; but since, in Florida, much of 
the surface is untilied, the evaporation for the whole State probably 
averages nearer the maximum than the minimum values given. 
The period of observation, from August 7 to August 14, falls in the 
hottest portion of the year, and this would give an abnormally high 
rate of evaporation, which might be in part counterbalanced by a 
high humidity accompanying the heavy precipitation of that part 
of the year. On the whole, an estimated surface evaporation of 20 
inches for the entire year is thought to be conservative. 

The quantity of water annually lost by evaporation from plants is 
sometimes regarded as insignificant; but this is by no means the 
case. The food which the plant derives from the soil is taken in 
solution in water, and this water, with the exception of what is 
built into the tissues of the plant itself, is largely evaporated from the 
surface of the leaves. Information concerning the quantity thus 
lost is fragmentary, and it is known that the amount differs with 
different kinds of plants and even with the same kind of plants 
under different conditions. The amount of water evaporated during 
the growth of a hay crop has been estimated at 5i inches; and 
the evaporation from a wheat crop at 2f inches.^ The early harvest- 
ing of the wheat crop permits the growth of another set of plants 
which probably remove nearly as much water from the earth as is 
evaporated by the wheat; and this raises the total evaporation from 
the area to about 5 inches per annum. 

Assuming that the evaporation from a citrus tree is approximately 
equal to that from the European evergreen oak — that is, 500 pounds 
of water to each pound of dry leaves — Hilgard ^ estimated the loss of 
water from a 15-year-old orange tree at 9 acre-inches. Riverside, 
Cal., where Hilgard worked, has an annual rainfall fully 15 inches 
less than the average precipitation in Florida and a higher evaporation. 
Hilgard also states that birch and linden trees give off 600 to 700 
pounds of water per pound of dry leaves, oaks 200 to 300 pounds, 
and conifers only 30 to 70 pounds. Since much of the vegetation of 
Florida consists of pine trees, the average rate of evaporation from 
trees in the State probably approximates that given for conifers. 
A conservative estimate of the average evaporation from plants in 
Florida is estimated to be about 5 or 6 acre-inches per year. This 
amoimt, added to the loss from the surface, is thought to equal 
approximately 25 acre-inches. Thus, though the annual addition to 
the undergroimd water is enough to cover the State to a depth of 
over 4 feet, the actual increase in the amount available for wells and 
springs does not exceed about 2 feet. 

1 Galloway, B. T., and Woods, A. F., Water as a factor in the growth of plants: Yearbook U. S. Dept. 
Agr., 1894, p. 174. 
8 HUgard, E. W., Soils, Macmillan Co., 1906, p. 263. 

76854°— wsp 319—13 15 



224 GEOLOGY AND GKOTJND WATERS OF FLORIDA. 

DEPTH TO UNDERGROUND WATER. 
WATER TABLE. 

Water absorbed by the soil moves downward until it reaches a level 
where the rocks are saturated. The upper surface of this saturated 
zone is known as the water table. The water table is not, as its 
name suggests, an even surface, for it slopes upward from the sea, 
rising beneath the hills and sinking in the valleys and reproducing 
with diminished relief and softened outlines the general configuration 




Figure 2.— Relation of underground-water level to Silver and Blue springs. 
E. H., Bull. Florida Geol. Survey No. 1, 1908, p. 32. 



Adapted from Sellards, 



of the surface of the land. The details of the form of the water 
table are largely influenced by the amount of water absorbed and the 
freedom of movement to points of escape, such as seeps and springs. 
In an arid region, where the rainfall is slight, the water table sinks 
far below the surface and becomes comparatively flat; in a humid 
region frequent rains make abundant contributions to the under- 
ground water and help to maintain the water table near the surface. 




Figure 3.— Relation of underground-water level to surface contour in Suwannee and Columbia counties. 
Adapted from Sellards, E. H., Bvill. Florida Geol. Survey No. 1, 1908, p. 32. 

The influence of rock texture on the size of the openings has already 
been mentioned; and, since the size and form of the openings affect 
the rate of movement of the underground water, they have an im- 
portant bearing on the form of the water table. Where the openings 
in the rock are large enough to permit the water to move freely, the 
water table will lose its inequalities under the influence of gravity. 
With the reduction of the size of the openings, friction retards the 
movement of the water, and finally, when the openings are of very 



UNDEKGEOUND WATER. 



225 



small size, both friction and capillarity tend to 
counteract the effect of gravity and to cause the 
configuration of the surface of the water table to 
approximate that of the land. 

The relation of the water table to springs, rivers, 
and lakes is similar to its relation to sea level. 
(See figs. 2,3, and 4. ) The underground- water level 
rises gradually from the borders of surface waters, 
as shown in figure 3, which is a generalized profile 
across the peninsula, with the surface of the ground 
represented by a solid line and the water table by 
a dotted line. Since the slope of the water table 
is toward the surface waters it follows that the 
normal flow of the ground waters is toward the 
bodies of surface water. This normal flow, how- 
ever, is sometimes reversed by a rapid rise in the 
level of the surface water. Periodical movements 
in the level of bodies of surface water, such as 
tides, are accompanied by corresponding fluctua- 
tions in the adjacent portion of the water table 
but are reduced in magnitude by friction. 

Where a portion of the ground water encounters 
a relatively impervious bed, it may be prevented 
from reaching the main body of the ground water. 
In this case, a local water table is formed which is 
entirely independent of the level of the great body 
of the groxmd water. Such a phenomenon is known 
as a perched^ water table. (See B.g. 4.) Usually 
more or less leakage to lower levels takes place 
from a perched water table because the material 
upon which the water rests is not whoUy imper- 
vious. 

DEPTH OF POTABLE SUPPLIES. 

Although a complete discussion of the potability 
of the Florida waters is beyond the scope of this 
report, it is necessary to consider briefly the gen- 
eral factors controlling the occurrence of water 
containing a high content of mineral matter in 
solution. The rocks of Florida are all sedi- 
mentary and for the most part were depos- 
ited beneath the ocean. Such deposits are 
called marine and originally include sea water, 
which may be designated water of deposition. 

1 Veatch, A. C.j Underground water resources of Long Island, N. Y.: Prof. 
Paper U. S. Geol. Survey No. 44, 1906, p. 57. 



tiUI 



1^ 



LaKeft^ir 



[StreoTrt 



jPerched. Spr 



Perched. 
\ water table 



Stream, 



IndiaMjUver 



226 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

This included sea water may be gradually displaced by descending 
rain water — the rate of change depending on the freedom of drainage. 
Where the rocks are porous and the land high the water of depo- 
sition is soon removed, but a low altitude combined with dense 
rocks gives a very slow rate of escape. The process of removal may 
extend some distance below sea level provided porous materials 
emerge on the bottom of the ocean. The exact depth will be con- 
trolled by the relative weights of the colunms of fresh water beneath 
the land and the salt water at the point of emergence. 

The greater height of the column of fresh water is partly offset by 
the increase of weight of the sea water caused by its high mineral 
content and by the friction of the water in the rocks. There must 
inevitably be a level where the opposing forces counterbalance each 
other and the underground water becomes nearly static. Below this 
level the water of deposition is scarcely disturbed, but its mineral 
character may be changed by osmotic action, by the solution of new 
substances, and locally by the deposition of some materials already 
in solution. In the older rocks of Florida the displacement of the 
water of deposition has been going on for a long time and the process 
has reached an advanced stage, but in the younger formations the 
time has been so short that some of the saline water still remains 
in beds near the surface, though it has usually been more or less 
changed in composition by the addition of rain water. 

In some localities a resubmergence of the older land has caused the 
rocks to become filled with a new supply of salt water, and hence the 
existence of such water does not necessarily mean that the conditions 
have always been unfavorable for its removal. 

In the northern part of Florida the salt water has usually been 
displaced to depths of at least 1,000 feet, though locally, as at Chat- 
tahoochee, some of the water obtained within less than 1,000 feet of 
the surface is somewhat saline. The conditions are illustrated by the 
1,100-foot well at Live Oak and the 1,001-foot well at Quincy, neither 
of which reports salt water. In the central part of the peninsula 
and extending as far south as Bartow and Mulberry, the conditions 
are similar to those in northern Florida. At Gainesville the well of 
the Diamond Ice Co. is 1,250 feet deep and encountered water that 
is slightly saline but that can be used as a city supply. At Plant City 
a 1,100-foot well procured fresh water, and, according to the reports 
from the drillers, a well 2,002 feet deep at Sumterville obtained no 
salt water, though this may not be correct as the well was not 
drilled for water and may not have been carefully tested to determine 
the quality of the water encountered. 

In passing from the interior of the State toward the coast the 
depth to salt water diminishes until in many localities it may be 



UNDEBGROUND WATER. 227 

encountered within less than 500 feet of th^ surface, though the depth 
to the strong brines is usually somewhat greater. Toward the south 
the horizons containing salt water lie nearer the surface, and it appears 
certain that on the southern end of the mainland and on the keys the 
fresh water is confined to the surficial rocks. This opinion was based 
largely on the increase toward the south in the percentage of salt in 
the deep wells and the diminishing depth to the saline water and is 
partly confirmed by the results obtained in drilling deep wells on the 
keys. 

Local areas of salt water were noted, among them being the ones 
at Enterprise, Titusville, and south of Kissimmee. At Enterprise 
and Titusville the water probably obtains its salt from materials 
deposited during a Pleistocene submergence. South of Kissimmee 
the salt water does not appear to have been removed from the younger 
rocks. Conditions similar to those just mentioned are known to 
exist on many of the low islands and keys bordering the coast. 

CIRCULATION OF UNDERGROUND WATER. 

Althofugh underground water often appears to be quiescent, in 
most localities it is moving very slowly through the rock toward some 
point of escape. The causes for this movement are several, but the 
most important is gravity. Gravity operates to bring underground 
water to the surface of the earth at a. lower level than that of the place 
where it entered and so enables it to join the surface water or to 
evaporate. Capillarity brings water to the surface, where it is 
evaporated, or brings it within the reach of plants which return it to 
the air. Flowing wells, which seem to act m opposition to gravity, 
are really due to that force acting upon a body of water which else- 
where extends to a level higher than that of the mouth of the well. 
Pressure exerted on the water-bearing beds may be a cause of move- 
ment of water, but in Florida this force has no noticeable effect. 

The rate of movement of underground water is determined by the 
same general factors that control the rate of movement of surface 
water, namely, friction and the slope of the water surface. The slope 
of the surface of the underground water (the water table) is generally 
slight but is in places high. Where the water table has a high slope 
the movement of the underground water might be expected to be 
rapid, but it is not necessarily so, because the friction is much greater 
underground than on the surface. In surface water the chief friction 
is that of the bed of the stream, whereas in underground water, 
except in caverns, it is that of the walls of innumerable small passages. 
In caverns the flow is comparable to that of surface streams, though 
where the channels are full there is the friction of the top of the chan- 
nel in addition to that of the bottom and sides. The temperature 



228 GEQLOGY AND GROUND WATERS OF FLORIDA. 

has been found to have a marked influence in rate of flow, increased 
temperature promoting its circulation through the pores in the rocks. 
It is difficult to compare the rate of flow of surface and underground 
water, but a safe generalization is that the movement of surface 
streams is to be measured in miles, and that of underground water 
through the pores of sands and limestones in feet or in inches. 

RECOVERY OF UNDERGROUND WATER. 

Recovery of underground water may be either natural or artificial; 
natural recovery may be either by seepage or springs and artificial by 
wells or infiltration galleries. 

NATURAL RECOVERY. 
SEEPAGE. 

As the term seepage is crommonly used it refers to water emerging 
from the earth in such a way that it does not form a stream. The 
presence of seepage is readily detected on many slopes where the 
surface soil is soft and boggy, but it is especially active at the con- 
tact between the water table and bodies of surface water such as 
streams and lakes. Seepage may be seen along many streams when 
the level of the surface water is sinking more rapidly than that of 
the ground water. Though usually inconspicuous, a large per- 
centage of the water which enters the earth is returned to the surface 
by seepage. Seepage water also emerges on hillsides where the water 
in its downward course comes in contact with impervious materials 
such as clay beds. 

Few seepage waters are highly mineralized, because in most locali- 
ties they travel only a short distance underground and in their 
course encounter little soluble matter. Much of the water derived 
from seepage on hillsides, however, is highly charged with organic 
matter which, in some localities, renders it somewhat objectionable. 
However, the water is seldom contaminated with substances dan- 
gerous to health except where it is obtained near dwellings. 

SPRINGS. 

Florida is noted for its springs, some of which, such as Silver Spring 
and Wekiva Spring (PI. XVII, B, p. 234), are very large. Two 
principal types are represented within the State, those in which the 
water emerges from the small pores in the rock at some favorable 
point, generally on a hillside, and those in which it follows a definite 
underground channel to the surface. In springs of the latter type 
some water is supplied from small openings in the limestone, but a 
great deal of it comes from caverns. 

Springs of the first type occur in all parts of the State, but are 
especially numerous in the north, where the Lafayette ( ?) formation 



UNDERGROUND WATER. 229 

lies near the surface. They occur on the hillsides or at the heads of 
ravines where the descending ground waters encounter relatively 
impervious materials. Though especially characteristic of the 
Lafayette ( ?) formation such springs also occur in the older Tertiary 
rocks and even in the sands of Quaternary age. 

Springs of the second type occur in parts of north Florida but are 
best developed in the central and western parts of the peninsula, 
where some of them give rise to navigable streams. The principal 
rocks which afford large springs are the limestones of the Vicksburg 
and Apalachicola groups, and of these the soft porous Vicksburgian 
limestones present the most favorable conditions for good flows. 
The size of some of the springs shows that these limestones must con- 
tain large underground channels, even though some of the water 
may be supplied by small passages in the rock. 

Some of the springs of Florida are remarkably free from mineral 
matter, but others contain large quantities of dissolved materials. 
Most water from the Lafayette (?) formation is but slightly miner- 
alized, though locally it contains more or less lime, magnesia, and 
iron. The limestone waters also contain lime and magnesia and 
other soluble substances common in such rocks. The springs of many 
localities are charged with a large amount of hydrogen sulphide gas, 
which appears to be derived largely from the decomposition of 
organic matter contained in the limestone. Many of the sulphur 
springs of the State are highly esteemed for their medicinal qualities. 
In some localities the water also contains enough salt to make it more 
or less saline. 

ARTIFICIAL RECOVERY. 
WELLS. 



Both shallow and deep wells are used in the artificial recovery of 
underground water. Infiltration galleries have nowhere been used 
for this purpose in Florida. Where practicable preference should 
be given to the deep wells, because they are least liable to be con- 
taminated by impure surface water. Shallow wells may be either 
dug, driven, or bored. Deep wells, though usually drilled, may also 
be driven or bored. 

The type of well to be sunk will depend upon the quantity, quality, 
and temperature of the water desired. A moderate quantity can 
usually be obtained from shallow dug or driven wells, but deeper 
wells will be needed for a large supply. If the water is intended for 
cooling, as, for example, in an ice factory, the most satisfactory 
supplies will be obtained at moderate depths. In general, it will 
also be found that the water from shallow wells contains less mineral 



230 GEOLOGY AKD GEOUND WATERS OF FLORIDA. 

matter than that from deep wells. In a densely populated region 
deep wells will be found most satisfactory as a source of drinking 
water, because when properly cased there is less danger of the water 
becoming polluted than in shallow wells. (See Pis. VI, B, p. 32; 
XVI, A.) 

POSITION OF WELLS. 

Several considerations should govern the placing of a well, only 
one of which — convenience — ^has generally been regarded. Though 
convenience is by no means unimportant, the probable depth to 
water and the quality, quantity, and static head of the supply could 
profitably be kept in mind. 

The depth to water is naturally influenced by the height of the 
surface, and, other things being equal, wells on higher ground must go 
deeper than those at lower levels to get the same amount of water. 
This statement may not hold for all wells drilled to the artesian- 
water beds, for these show marked differences in depth that are 
entirely independent of the surface configuration. 



_Location of bu i Id i ngs 



Direction of movemenf of ground wa+er 



Wa+er+able — -__ _ _ _ _~;;;;^^5^i^^ed^iorrof^J^^^^ ^ 



Figure 5.— Diagram showing importance of choosing proper locations for wells, a, Well improperly 

placed; b, well properly placed. 

The static head of the water determines the height to which it will 
rise in the well, and should be carefully considered if a flowing well is 
expected. Moreover, in Florida a boring for a flowing well should 
if possible be made at a point where the water will rise 4 or 5 feet 
above the surface during a wet season, this margin being ordinarily 
sufficient to counterbalance a temporary decline of head caused by 
droughts. 

If the water is to be used for domestic purposes and especially for 
drinking, several other factors must be considered, the most impor- 
tant beiag the possibility of pollution by impure surface drainage. 
This involves a consideration of the location of the intake and the 
direction of movement of the underground water. Since artesian 
wells are supplied by water which has moved for long distances 
through porous rocks, the supply is usually free from pollution, except 
as a result of imperfect casiag, permittiag the entrance of objection- 
able matter. The purity of the water from the artesian weUs is due, 
in part, to the fact that it undergoes fUtration during its passage 
through the minute pores of the rock. 

Where the well is supplied by water which has only a short under- 
ground circulation, the source and direction of movement become 
very important. This is illustrated by figure 5, where the movement 



sV 


H •• < 


1 


^^HHi ;l ^1 


1 


^H^^BHi^K''* 


BT^ 


H^^**""" 


W J 


1 ^H^^^^^^^^Klk m, ■ --^ 


1 






i 



UNDERGROUND WATER. 231 

of the ground water is from the buildings toward the well at a, making 
the well liable to receive a constant supply of impure water, which may 
become dangerous whenever the polluting matter contains any of the 
germs of disease. The placing of the well at h (fig. 5) would have 
obviated such a danger and insured a supply of pure water. 

METHODS OF WELL MAKING. 

The method to be used in sinking wells is determined by the character 
and depth of the well desired, the nature of the material to be pene- 
trated, and the amount of money to be expended. 

Dug wells. — Dug wells are excavated with a pick and shovel, and 
the loosened material is removed by a bucket and windlass. Dug 
wells are put down chiefly in unconsolidated materials and have the 
advantages of simplicity and ease of construction. Since dug wells 
are necessarily of large diameter, they offer a large surface for the 
entrance of water and hence are well adapted to deposits that yield 
their supply slowly. In depth few wells of this type exceed 40 or 50 
feet and most of them are less than 30 feet deep. 

One of the principal objections to the dug well is that it receives a 
large amount of water from near the surface and is therefore likely 
to become contaminated. It is probably no exaggeration to say that 
such wells have been a very prolific source of dissemination of typhoid 
fever. 

In Florida the use of dug wells is almost wholly confined to the 
northern end of the State, where the settlements antedate the intro- 
duction of improved weU-drilling machinery. A large number of 
these old weUs are still in use, but they are gradually being -replaced 
by wells of more modern type. 

Bored wells. — Bored wells are constructed by the use of an earth 
auger operated by hand or power. The auger is turned by means 
of horizontal bars attached to a vertical rod, and must be raised fre- 
quently in order to remove the loosened material. 

Bored wells are put down only in unconsolidated materials and 
range in diameter from 2 inches to a foot or more. Where the material 
is very soft, a casing having a diameter slightly greater than that of 
the auger is forced down around it to prevent the walls from caving. 
The casing is commonly made of wood, though in some weUs tile is 
used. Wooden casing is not entirely satisfactory because it may 
permit the entrance of surface water unless it is well constructed and 
protected from decay. Tile is much more durable and hence more 
satisfactory. In most wells the exclusion of contaminated surface 
water would be rendered more certain if the joints between the suc- 
cessive sections of the casing were firmly cemented. Iron pipe may 
also be used for casing, but tile is equally good and is less expensive. 



232 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

Bored wells, when properly cased, form a very satisfactory means of 
supply. 

In Florida bored wells are restricted almost wholly to the northern 
part of the State, where there is a thick mantle of incoherent sands 
and sandy clays. Few of these wells exceed 125 to 130 feet in depth. 

Driven wells. — Wells are driven by forcing an iron pipe into uncon- 
solidated materials. The pipe is commonly fitted with a perforated 
metal screen which tapers to a point and which permits the entrance 
of water and prevents the pipe from becoming clogged by sand or 
clay. Wells of this t3rpe are especially adapted to formations in 
which the permanent ground-water level is within less than 30 feet 
of the surface, so that the water can be raised by a suction pump. 
Driven wells of large diameter, however, may be fitted with force 
pumps, and hence they are adapted to formations where the water 
level lies below the limit for the successful operation of suction 
pumps. 

In Florida few driven wells exceed 2 inches in diameter and most 
of them are comparatively inexpensive. In some places wells are 
sunk by driving a pipe into the ground and removing the sand or 
clay by means of a bucket, but this method is seldom employed in 
Florida. 

Drilled wells. — Of the several types of drilling apparatus only 
two — the cable and the jet rigs ^ — are in common use in Florida. 
Both are well adapted to the soft rocks of most of the State, but the 
cable rig is most extensively used where wells are to be sunk to the 
artesian water beds of the Oligocene limestone. In the cable rig the 
cutting is done by means of a wedge-shaped piece of steel, which is 
raised and dropped by machuiery. The cutting bit is usually 
attached to a bar which gives added weight and increases the force 
of the impact. The raising and lowering of the drilling tools is 
accomplished by means of a cable which passes over a pulley attached 
to a derrick. As the drill is dropped it is given a slight rotary motion 
by turning the cable. In some wells two bars are introduced between 
the cable and the drilling bit. These bars are linked together in such 
a way that a play of 6 or 8 inches is allowed and when the tools are 
lifted this play gives an upward jerk which helps to loosen the 
bit. In Florida these supplementary bars (called ^^jars") are usually 
omitted, as the rock is of such a character that there is little danger 
of the drill becoming fast in the hole. In using the cable rig it is 
necessary to withdraw the drill at frequent intervals and remove the 
broken rock from the bore by means of a sand bucket. In some types 
of rigs the drillings are removed automatically, but such drills have 
not *been extensively used in Florida. In using the cable drill it is 

1 For detailed discussion see Bowman, Isaiah, Well-drilling methods: Water-Supply Paper U. S. Geol. 
Survey No. 257, 1911. 



k 



UNDERGROUND WATER. 233 

necessary to drive the casing to the first hard rock in order to exclude 
the soft surficial sands and clays. Below this few wells are cased, 
though some are continued with a casing of smaller diameter. Cable 
drills are especially adapted to drHliag deep artesian wells, in which, 
in Florida, many beds of chert are encountered. 

The jet process differs from the ordinary cable method in that the 
drill is not raised and dropped except where hard beds are encountered. 
The ordinary method is to force water into a small pipe which is 
fitted with a bit at the lower end. The force of the jet of water is 
directed against the bottom of the hole and helps to loosen the par- 
ticles of clay and sand. The drill is slowly rotated just as in the use 
of the cable rig. The water rises in the bore and carries the loosened 
material with it to the surface. 

Drilled wells are adapted to hard rocks and when properly cased 
are exceptionally free from danger of contamination by impure sur- 
face waters. Drilled wells are found in nearly all of the inhabited 
portions of the State, but they are especially numerous along the 
east coast, from Fernandina southward, in the St. Johns Valley, and 
along the west coast from Tampa to Fort Myers. In these localities 
large numbers of wells have been sunk to the artesian water beds. 
They not only supply houses, farms, and cities but also serve as val- 
uable sources of water power. 

METHODS OF RAISING WATER. 

Where, as at numerous localities along the east coast and at 
Manatee and Fort Myers on the west coast, the static head is sufficient 
to raise the water to the height desired by the consumer, no special 
apparatus for raising water is needed. In such localities the water is 
piped to the points where it is to be used, and the natural head of 
the well furnishes the pressure. In this way the towns of Green 
Cove Springs, South Jacksonville, Fort Myers, and Freeport, and 
numerous minor places are furnished with all the conveniences of 
water systems without the necessity of pumping plants, tanks, or 
standpipes. 

Where weUs flow only a few feet above the surface, it is sometimes 
possible to force the water to higher levels by means of hydraulic 
rams or water wheels. This method, which has been adopted with 
very satisfactory results, enables the owner of a well to raise water 
to a considerable height above the well without additional expense 
beyond the cost of the hydraulic ram or water wheel. Many hotels 
and private houses along the east coast of Florida are equipped with 
raised tanks which are filled in the manner described above. In 
some localities enough water is raised to irrigate gardens and orange 
groves, but most supplies are too smaU for such purposes. 



234 



GEOLOGY AND GKOUND WATEES OF PLOEIDA. 



Where wells do not flow or where the flow is not sufficient to meet 
the needs of the well owner, it is necessary to resort to some artificial 
means of raising water. The most common are the old-fashioned 
bucket and windlass or the hand pump. These two methods are 
satisfactory where a small amount of water is desir*ed for domestic or 
farm use, but where large supplies are required some form of power 
pump, operated by steam or gasoline engines, is installed. In a few 
places windmills, water wheels, or electric motors are used to supply 
motive power. (See PL XVII, A.) 

UNDERGROUND WATERS OF CENTRAL AND NORTHERN 

FLORIDA. 

By G. C. Matson. 
ARTESIAN WATER. 



ARTESIAN REQUISITES. 



The limestones of the Vicksburg group are the important artesian 
water-bearing beds of Florida. In fact, with a few exceptions the 
rocks of this group supply the water for the flowing wells of the State. 
The early theories concerning the cause of artesian pressure postulated 



Surficial sand 




Figure 6.— Conditions governing the occurrence of artesian water in some parts of Florida. 

a basin structure for the porous bed. However, this structure is now 
known to be uncommon and wholly unnecessary. It is certain that 
no such structure exists in the artesian areas of Florida. Another con- 
dition which gives rise to artesian waters is shown in figure 6, which 
shows the water passing downward through inclined beds, forming 
an artesian slope. The porous bed may be terminated by impervious 
material or may be continued for a long distance. 

Much water passing outward from the central portion of the 
peninsula of Florida descends beneath hard layers of chert, which 
offer considerable resistance to its upward movement. This con- 
dition is shown graphically in figure 6, which is a vertical section 
extending from the central part of the peninsula eastward beyond 
the coast line. In this figure a and h represent water-bearing beds 
confined beneath relatively impervious beds of chert. Above c is 
another porous bed which contains more or less water, which is not 
confined by dense rock. The conditions shown in this figure differ 
radically from some of the earlier ideas concerning the occurrence of 



U. S. GEOLOGICAL SURVEY 



WATER-SUPPLY PAPER 319 PLATE XVII 




A. WATERWHEEL FOR PUMPING WATER, CALOOSAHATCHEE RIVER. 




B. WEKIVA SPRING, SHOWING SPRING AND BATHHOUSE. 



UNDEKGKOUND WATERS OF CENTRAL AND NORTHERN FLORIDA. 235 

artesian water, but the water confined within the porous layers a and 
h is under hydraulic pressure and is to be regarded as artesian, though 
in some parts of the section the pressure is not sufficient to lift it 
above the surface. This figure illustrates the conditions which con- 
trol the occurrence of artesian waters in all the principal flowing-well 
areas of Florida. In many localities there are two or more artesian 
beds separated by successive layers of chert. 

The occurrence of the artesian waters depends on several factors, 
which have sometimes been designated ^^artesian requisites." The first 
is an adequate rainfall to supply the water, and this requirement is 
met by the large annual precipitation of the region. The second 
requisite is a porous water bed, and this is furnished by the loosely 
aggregated limestones of the Vicksburg group. The third requisite 
is the practical exposure of the porous bed to form a catchment area. 
The principal catchment area of this limestone occupies a belt in the 
central portion of the peninsula and extends northward into Georgia. 
A subordinate area is located in west Florida, where it occupies a 
tract of land extending from near Chipley northward into Alabama. 
The fourth requisite is a confining layer of relatively impervious 
rock, which, as already explained, is furnished in Florida by layers 
of chert. In some places there is a second layer of chert below the 
artesian bed, but this is not essential, because the rocks below the arte- 
sian bed are saturated with water. The fifth requisite is an inclination 
of the water-bearing bed, and this is supplied by the dip of the 
limestone away from the center of the peninsula and outward from 
the adjacent mainland. 

HEAD OF ARTESIAN WATER. 

CONTROLLING FACTORS. 

The principal factors which control the hydraulic pressure of the 
artesian water are the altitude of the water table beneath the catch- 
ment area, the resistance to the movement of water through the 
porous bed, and the perfection of the relatively impervious layer 
which caps the aquifer. Reference to the topographic map (PL I, 
in pocket) shows that the catchment area of the Vicksburg lies almost 
wholly below 200 feet and that the water table in the higher areas is 
some distance below the surface. The altitude of this water table is 
probably in few places above 150 feet, and over a large part of the 
central portion of the peninsula it is less than 100 feet above sea level. 
This explains why the artesian head in Florida is not so great as in 
regions where the catchment areas are located on the flanks of moun- 
tain ranges. 

The resistance which the rock offers to the movement of the 
artesian water diminishes the head, and consequently, where the 



236 GEOLOGY Al^D GEOUND WATERS OF FLORIDA. 

other factors are equal, the height to which the water will rise is 
controlled by the porosity of the rock and the distance of the well 
from the catchment area. If there is no change in the texture of the 
rock, the head will decline gradually in passing outward from the 
catchment area. Locally the head is greatly affected by the char- 
acter of the confining layer. In some localities, where this layer is 
more or less broken and discontinuous, considerable water escapes 
and the hydraulic pressure in the surrounding area is lessened. 

ARTESIAN HEAD IN FLORIDA. 

Along the east coast. — The head of artesian water varies consider- 
ably along the east coast of Florida, the range being from 65 feet 
above sea level at Jacksonville to only a few feet above farther south. 
This variation was at first supposed to result from differences in the 
height of the catchment area. The water at Jacksonville is doubtless 
partly supplied from the outcrops of the Vicksburgian limestone in 
southern Georgia, where the land is high, and thus the theory that 
variations in the head are due to corresponding variations m the 
altitude of the catchment area appears to be partly substantiated. 
However, when an attempt is made to extend this explanation to the 
entire artesian belt of the east coast, it is at once apparent that other 
factors are also involved. At Jacksonville water will rise 65 feet 
above sea level; at St. Augustine, 35 feet; at Daytona, 14i feet; at 
Seabreeze, 5 feet; and at Eau Gallic, 50 feet; this indicates that the 
head falls gradually and then rises again to more than 60 per cent of 
the maximum. 

Aside from the influence of the altitude of the catchment area, 
the important factors which influence the head are the perfection of 
the confining bed and, to a less degree, the friction in the porous 
water-bearing bed. Doubtless the amount of friction varies from 
place to place, but as far as may be judged by the character of the rock 
its influence is for the most part of very little importance in deter- 
mining the head. The perfection, however, of the confining bed 
which caps the artesian stratum has a very important bearing on the 
pressure. At St. Augustine and Daytona the decline in head appears 
to be largely due to this cause, as shown by the existence of the near- 
by large submarine springs. The most important of these is located 
off St. Augustine, and a similar spring is reported near Port Orange, 
which lies just south of Daytona. Though few springs are apt to 
exercise so wide an influence as is noted in the head of the wells along 
the east coast, it is probable that the known springs, large though 
they be, represent only a small portion of the total submarine dis- 
charge in the localities mentioned. At Daytona the presence of 
artesian water above the chert bed which caps the principal water 
bed suggests local imperfections which permit considerable leakage. 



UNDEKGROUND WATERS OF CENTRAL AND NORTHERN FLORIDA. 237 

This view is strengthened by the fact that the water above the chert 
bed possesses some of the mineral characteristics of that below, being 
charged with hydrogen sulphide. 

Head in the interior. — In the interior of the State the head of the 
artesian waters is in places high. At Sanford it is approximately 25 
feet above sea level and at Kissimmee is about 75 feet above, this 
probably being the maximum head in the State. The conditions at 
Kissimmee are exceptionally favorable, for dense materials above 
the limestone reenforce the cap rock and thus effectually prevent 
leakage, and to the south the limestones are so deeply covered that 
leakage is prevented. In addition to the flowing wells from the 
Vicksburgian, the Quaternary and perhaps the younger Tertiary 
furnish flowing wells near Kissimmee. 

Head in southern Florida. — The head of the artesian water dimin- 
ishes to the south, and along the main chain of the keys the water 
will probably not rise above sea level. 

Head on the west coast. — On the west coast of the peninsula the head 
of the artesian water increases toward the south. Thus at Tampa it 
is approximately 17 feet above sea level; at St. Petersburg it is also 
low; at Manatee and Bradentown it rises to about 25 feet, and at 
Fort Myers it reaches a maximum of nearly 45 feet. This increase in 
head is apparently due to the fact that the water-bearing rocks are 
more perfectly capped by the relatively impervious cherts and clays 
at Manatee, Bradentown, and Fort Myers than at Tampa and St. 
Petersburg. The efficiency of the cap rock seems to increase toward 
the south, where the dip of the artesian beds carries them to consider- 
able depth below the surface. This is probably due in part to the 
greater thickness of superincumbent clays, and in part to the fact 
that the artesian beds have not been so extensively eroded as they 
have farther north ; hence the chert beds are much more continuous. 

In general the artesian areas of the Gulf coast of west Florida have 
a good head, and, so far as known, they present no unusual features. 
The beds yielding artesian water are probably in part younger than 
the Oligocene, but their exact age is not everywhere determinable. 
In the vicinity of Freeport the water rises to about 22 feet above sea 
level; at Apalachicola and Carrabelle it is reported to rise to a 
slightly less height but still to one sufficient to give good flowing wells. 

CHANGES IN ARTESIAN HEAD. 

The height to which the artesian water will rise is subject to certain 
changes, which may be due either to natural or artificial causes and 
which may be transitory or permanent. 

Natural causes. — The variations most often noted in Florida are 
those caused by tidal fluctuation or by changes in rainfall. Varia- 
tions in barometric pressure may temporarily afi'ect the artesian 



238 GEOLOGY AND GROUND WATEKS OF FLOEIDA. 

head, but the magnitude of such changes is so slight that it is seldom 
noted. Tidal movements, however, affect the head and yield of 
wells near the coast so noticeably that the result is recognized by 
practically every owner of a flowing well near the sea. A rise of the 
tide causes a corresponding increase in the head and a fall of the tide 
is accompanied by a decline, the common range in Florida being 
from 1 to 2 feet. In some places where wells haye sufficient head to 
bring the water near the surface at low tide flows may take place 
during high tide, and thus the wells flow intermittently. A well of 
this type is located near HUlsboro River at Tampa. The cause for 
tidal variations is to be found in the amount of pressure which the 
sea water exercises on the rock which caps the artesian beds. As the 
tide rises the height of the column of water pressing upon this cap rock 
is increased, and as it falls the height is diminished. The conditions 
governing the head at any particular locality are so nicely balanced 
that the additional weight of a column of water a few inches in height 
will produce a change in the height to which the water rises in adja- 
cent wells. 

Variations in the amount of rainfall produce a marked effect on the 
artesian head. This is noticed first on the outskirts of the artesian 
areas, where the hydrostatic pressure is just sufficient to produce a 
flow under the most favorable conditions. In such situations a 
marked deficiency in the amount of rainfall may cause the wells to 
cease to flow and the water level may sink a few feet below the surface. 
Wells which have stopped flowing during prolonged drought are by 
no means uncommon. With an increased rainfall the head may be 
restored and the water may again rise above the surface. 

The changes in head are in part due to variations in the level of 
the water table beneath the catchment area and in part to the fluctu- 
ations iu the height of the water table near the well, or to the weight 
of the water which has entered the ground. The variation in the 
height of the water table at the well is of minor importance and acts 
in much the same way as does the tide on the head of wells near the 
seashore. With increased rainfall the quantity of ground water in 
the vicinity of the well is augmented and the increased weight of the 
column of ground water upon the rock which caps the artesian beds 
adds to the hydraulic pressure of the water in those beds and in- 
creases the height to which it will rise in the well. The results of 
this pressure are usually felt within a very short time after a heavy 
rain and they may be of either long or short duration, dependiag 
entirely on whether the origiaal level of the ground-water table is 
restored promptly. Fluctuations of this character may result as 
soon as water enters the soil and before it reaches the water table. 
In such cases the pressure is transmitted from the saturated upper I 



Ul^DEBGROUND WATERS OF CENTRAL AND NORTHERN FLORIDA. 239 

layers of the soil to the water table by the air confined in the soil. 
The change produced by variations in the altitude of the water table 
beneath the catchment area takes place slowly, but under very 
favorable conditions it may materially raise the water level in the 
well. Thus wells which have ceased to flow during a period of low 
rainfall may begin to flow during a period of heavy precipitation. 
There are other natural causes for fluctuations of water levels in wells, 
among them being changes in temperature and clogging of the water- 
bearing rock. 

Artificial causes. — Of the artificial causes which may produce 
changes in the head of artesian water, one of the most important is 
the large demand made by the flow of numerous wells, which may 
lower the head within a short time. Thus, at Daytona, where a large 
number of wells have been drilled within the city limits, the head is 
reported to have fallen more than 2 feet since the first wells were 
sunk. The decline in head of a well may sometimes be due to clog- 
ging of the bore by mud or sand, or even to the growth of micro- 
scopic plants. This last is extremely rare and changes due to clog- 
ging take place in few wells that are properly cased. Since decline 
in the head of water is accompanied by a decrease in the artesian 
area and diminution in the quantity of water obtained from the flow- 
ing wells, the change is usually stated in the amount of decrease in 
flow rather than in loss of head. Some excellent illustrations of this 
character are supplied by geologists who have investigated the water 
resources of areas in the valley of southern California. The following 
table, taken from a report by Mendenhall ^ shows the decrease in 
water derived from the flowing wells and springs, and a corresponding 
increase in the amount of water pumped (developed water) : 



Relations of pumped water and water from flowing wells in southern California. 

[In second-feet.l 



Date. 



Flowing 
water. 



Devel- 
oped 
water. 



Total. 



September, 1898 

August. 1899.... ■ 

September, 1900 

September, 1902 

August and September, 1903 
August, 1904 



78.31 
44.68 
54.18 
38.52 
45.55 
38.62 



66.38 
65.46 
71.42 
81.69 
109. 70 
105. 36 



144. 69 
110. 14 
125.60 
120. 21 
155. 25 
143. 98 



Though little change has taken place in the total quantity of water 
used, the ratio of flowing water to pumped water has changed from 
1 to 1 in 1891 to 1 to 3 in 1903. This change is due to the fact that 
the head of the water diminished so that pumping was necessary to 

» Mendenhall, W. C, Hydrology of San Bernardino Valley, Cal.: Water-Supply Paper U. S. Geol. 
Survey No. 142, 1905, p. 63. 

76854**— wsp 319—13 16 



240 



GEOLOGY AND GEOUKD WATERS OF FLORIDA. 



get an adequate supply. The decline in head of wells is shown 
graphically by figure 7.^ 

The conditions in California are exceptionally favorable for illus- 
trating loss of head, because the rainfall is small and the effect of a 
large withdrawal of water is felt within a few years. In Florida, 
where the rainfall is very heavy, such changes would take place so 
slowly that they could be detected only by observations extending 
over a much longer period of time. However, there can be little 
doubt that the large supplies which are being withdrawn from the 
artesian beds of certain areas where irrigation is practiced will ulti- 



Fift from 

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June to Dec. 


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Figure 7.— Variation of water level in Jolmson well, near San Bernardino, Cal. 

mately lower the head of the artesian water. This lowering will not 
only operate to diminish the yield of wells, but it will cause wells on 
the higher ground near the borders of the artesian area to cease flow- 
ing. To prevent loss of head, wells should be closed when not in use. 
(See PL XVI, B, p. 230.) 

One of the important factors operating to produce a change in the 
head of the water is the rate of withdrawing water by pumping. In 
Florida, pumping has not yet been done on a sufficiently large scale 
to produce marked effect on the ground-water table, but in some 
other States the water level has been materially lowered by this 
means. When a well which draws its supply from the ground water 

1 Mendenhallj W, C, op. cit., p. 62, 



UNDERGROUND WATERS OF CENTRAL AND NORTHERN FLORIDA. 241 

is pumped rapidly, a cone-shaped depression develops around the well 
in the surface of the water table, the size of the depression and the 
steepness of its slope depending chiefly on the rate of movement of the 
water toward the well and the rapidity with which it is removed. 
The effect of pumping a single well is usually local and its duration 
temporary, but when a large number of wells occupying a small area 
are pumped rapidly an extensive depression of the water table may 
result. In such areas, if the demand does not exceed the supply, 
no permanent lowering of the water table results. The length of 
time required for the original water level to be restored will depend 
on the rate of movement of water from the adjacent region into the 
area affected by pumping. Excessive pumping and unlimited flow 
from wells are the most important artificial causes for fluctuations in 
the level of the underground water, but many other factors are 
important. Among these are cultivation of the soil and obstruction 
to free movement of water to points of escape. 

Cultivation, by loosening the surface material, may permit in- 
creased absorption, but unless the surface is kept loose the subsequent 
movement of water through the capillary pores of the soil and its 
evaporation from the surface may neutralize the effect. Different 
crops also have different effects on the ground-water level, for some 
plants remove more moisture from the soil than others. The effects 
of fertilizers vary with the kind and amount of material added to the 
son. Some fertilizers increase absorption by increasing the size of 
the openings between the soil grains; others increase the amount of 
evaporation. 

Obstructions to the percolation of ground water are dams, which 
raise the level of the surface water and the adjacent portion of the 
ground-water table, and irrigation, which practically raises the level 
of the ground water in the irrigated area by actual additions. How- 
ever, few changes due to the irrigation and the construction of reser- 
voirs and dams are of more than local importance, and, where the 
ground water is used, the amount withdrawn may more than coun- 
terbalance the rise due to these causes. 

ARTESIAN FALLACIES. 

The belief, prevalent in many parts of the country, that the head 
of water increases with the depth of the well has frequently been 
given weight by the fact that certain deep wells have a much greater 
head than the shallow wells of the same region, though ordinarily it 
appears to be merely a corollary of the theory that flowing wells can 
be obtained anywhere if wells are sunk to sufficient depths. At pres- 
ent no evidence exists that the head of the Florida waters increases 
below the level of the main water-bearing beds, and the sinking of 
wells far below the principal artesian stratums has commonly resulted 



242 GEOLOGY AND GROUND WATERS OF FLORIDA. 

in the discovery of higKly mineralized waters rather than in an in- 
creased head. In some wells the failure to obtain flows may be due 
to defective casings, and in such the only remedy is to insert a water- 
tight casing to the top of each successive water-bearing stratum, 
where there is more than one, in order to test the height to which the 
water from the different beds will rise. 

OCCURRENCE OF UNDERGROUND WATER. 

WATER-BEARING MATERIALS. 

Character. — ^The mode of occurrence of underground water varies 
with the character of the materials. In Florida, the most important 
types of water-bearing deposits are limestones, sands, sheU marls, and 
clays. Although some of these materials occur nearly pure, they are 
more commonly found mixed in different proportions. The water 
in the formations is included in openings ranging in size from the 
tiniest threads to caverns several hundred feet in diameter, which, 
though striking, contain, on the whole, much less water than is held 
in the small passages between the individual grains of the rock. 

Sand and gravel. — Sand and gravel are excellent water-bearing 
materials, both for volume and quahty of supply. The water occurs 
in openings between the grains and the amount in any particular 
bed depends on the pore space and the degree of saturation. The 
amount of pore space varies with the size and shape of the grains and 
it may equal or exceed 20 per cent of the volume of the materials. 
The largest pore space is found in even-grained sand or gravel; and 
the mixing of coarse and fine material reduces the size of the open- 
ings and lessens the total porosity. Much of the water held by sand 
and gravel is readily available to wells and springs, because the open- 
ings are large enough to allow the water to move freely under the 
influence of gravity. Some sands, however, are very unsatisfactory 
water beds because their grains are so small that it is impossible to 
exclude them from the pipes and pumps, where they are apt to do 
much damage either by clogging the well or by ruining the machinery. 
Water from sand is generally of excellent quahty because the impuri- 
ties are usually filtered from it during its passage through the small 
pores. An exception to this is found in the coarse-grained sands, 
where the passages are so large that the water receives Httle or no 
purification. Practically any type of well is satisfactory in sand and 
gravel, but drilled or driven wells are best, because they may be easily 
cased to prevent the entrance of surface drainage. 

Clay. — Contrary to the usually accepted idea clays may contain an 
abundance of water. The amount of pore space may equal or exceed 
one- third of the volume of the material; but the amount of available 
water is much less than might be expected from such a high porosity, 
because the openings are so small that the water is held tenaciously 



UNDEKGKOUND WATERS OF CENTRAL AND NORTHERN FLORIDA. 243 

and moves very slowly to points of escape. The water obtained from 
clays is usually highly mineralized because it has remained long in 
contact with the soluble mineral matter in the rock. If it is neces- 
sary to rely on clay beds for a water supply, dug wells will be found 
most satisfactory, for such wells afford a large surface for the entrance 
of water by slow seepage. Drilled, driven, or bored wells are apt to 
be unsuccessful. 

SJiell marl. — Shell marl is made up of shells more or less firmly 
embedded in a matrix of sand or clay. The shell marls of Florida have 
a sandy matrix and their water capacity may be nearly as great as 
that of sands. In general they contain more or less carbonate of 
Hme, which occupies the space between the sand grains and dimin- 
ishes the pore space. The quantity of water derived from such 
materials is usually ample for ordinary domestic or farm uses. Wells 
of small diameter are nearly always successful where they penetrate 
the marls below the permanent water level, though where the mate- 
rials are exceptionally close grained it may be necessary to sink dug 
wells. Carbonate of lime and other soluble compounds are abundant 
in the marls and the solution of these makes the water hard, the degree 
of hardness varying with the freedom with which the water circu- 
lates and the length of time it remains in contact with the soluble 
substances. 

Limestone. — ^The water capacity of limestones differs with the 
character of the rock. In Florida many of the limestones are porous 
and contain large supplies of water occupying small openings between 
the grains of the rock. In addition they contain many crevices and 
caverns, which supply water readily to weUs or give rise to springs, 
some of which are very large. (See pp. 228-229.) Where the small 
openings fail to yield sufficient water a well is usually continued until 
it reaches a crevice or a cavern. Owing to the irregular distribution 
of the underground channels, it is not possible to predict the depth at 
which one will be found, and weUs a few feet apart may obtain their 
supphes at different depths. Most limestone waters are hard, 
because they contain materials dissolved from the rock. The most 
common mineral constituents of such waters are carbonates of lime 
and magnesia, but many other compounds are present in small quan- 
tities. Owing to the fact that surface water may enter the under- 
ground channels through open sinks, hmestone waters are easily 
contaminated, especially near dweUings, and in case of pollution 
have little opportunity for natural purification. 

WATER-BEARING FORMATIONS. 
GOVERNING CONDITIONS. 

The hydrologic values of different stratigraphic units differ, depend- 
ing on the character, thickness, and position of the beds. The character 
of the beds is especially important, sandstones and porous lime- 



244 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

stones being better sources of water than dense limestones and clays ; 
for example, the sands of the Alum Bluff formation or the porous 
Vicksburgian limestones are much more important water-bearing 
rocks than the clays of the Hawthorn formation or the dense lime- 
stones of the Chattahoochee formation. 

The thickness of the different stratigraphic units may be important 
where the beds are near the surface; this fact is well shown by the 
Pleistocene sands, which may contain httle or no water where they 
form a thin deposit on the upland, but which are the source of large 
supphes near the coast and in the southern part of the peninsula, 
where they attain considerable thickness. However, a thin porous 
bed lying below the level of the water table is in many places a 
very important aquifer. 

The position of the water-bearing rocks generally has a marked rela- 
tion to their water value. In the central part of the peninsula porous 
rocks of Vicksburg age he partly above the level of complete saturation, 
and in places wells must be sunk some distance into the porous beds 
before they obtain permanent supphes. Nearer the coast the porous 
beds lie below the level of the water table and will yield an abundance 
of water throughout their thickness. 

Close relation also exists between the quality of the water and the 
character and position of the beds. Water from insoluble materials, 
such as sands, is usually soft or only moderately hard; that derived 
from soluble rocks, such as limestones and marls, commonly con- 
tains considerable mineral matter and may be quite hard. The 
character of the beds may influence the quahty of the water by con- 
trolhng the rate of circulation, for, other factors being equal, the 
porous rocks will permit rapid circulation of the water and the amount 
of solution will be small, whereas the dense rocks will retain the 
water in contact with soluble matter for a longer period and thus 
afford opportunity for its being dissolved. The position of the 
water-bearing rocks may have an influence on the rate of circulation 
and thus affect the quality of the water. In varying positions the 
same water bed may yield water having different qualities, depend- 
ing upon the rate of circulation and the distance the water has 
traveled through the rocks. In marine formations, such as are 
found in Florida, the quality may also be affected by the presence 
of included sea water, which has not been removed because the 
position of the beds does not permit it to escape readily. 

In the discussion which follows the water values of the various 
stratigraphic units are outlined briefly; the detailed discussion of 
the quantity and. quality of the water from the different water- 
bearing beds is given in the county descriptions. A general summary 
of the water-bearing formations is given in the following table: 



tTNDEKGEOUND WATERS OF CENTRAL AND NORTHERN FLORIDA. 245 



>1 

ft 
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Of very little importance, but may 
furnish some water for shallow 
wells. 


The sands are an important source 
of water except on the uplands, 
where they are thin. The other 
kinds of rock in few places furnish 
much water. In southern Florida 
large quantities of water are ob- 
tained from the Miami oolite and 
underlying beds of siliceous sand 
and shell fragments. 


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GEOLOGY AND GBOUND WATERS OF FLORIDA. 





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UNDEEGEOUND WATERS OP CENTEAL AND NORTHEEN FLOEIDA. 247 



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248 GEOLOGY AKD GROUND WATERS OF FLORIDA. 



WATER IN THE OLIGOCENE SERIES. 
IMPORTANCE. 



Oligocene rocks contain the best water-bearing beds in Florida. 
The porous limestones of the Vicksburg group are not only the most 
important source in the large areas of flowing wells, but they also 
furnish the largest supplies in areas where wells do not flow. More- 
over, the large springs of the State nearly all emerge from the Vicks- 
burgian rocks, either directly or through openings in the younger 
formations. The Apalachicola group is a much less important 
source than the Vicksburgian limestones. The water capacity of its 
formations differs greatly, the best supplies being found in the lime- 
stones of the Chattahoochee formation and in the sands of the Alum 
Bluff formation. These two formations, though less important than 
the Vicksburgian limestones, are more valuable sources of supply 
than are some of the younger rocks. 

WATER IN LIMESTONES OF THE VICKSBURG GROUP. 

Although the large underground channels formed as a result of solu- 
tion of the rocks of the Vicksburg group (pp. 25-29) are numerous, 
it is doubtful if their aggregate capacity is as great as that of the 
more or less minute passages between the individual grains of the 
limestone, which bear a striking resemblance to the water-bearing 
pores in sandstone. Though the limestones of the Vicksburg group 
contain layers of comparatively dense rock, as a whole they are open 
and porous, so that their water-bearing capacity is comparable to 
that of the important water-bearing sands farther north along the 
Atlantic coast. In some localities where the limestone is cavernous 
it probably contains a higher percentage of water than is held by an 
equal volume of sand. 

The movement of the water through the Vicksburgian limestones 
takes place under the influence of gravity, and is in part in the form 
of underground streams, many of which have considerable volume, 
and in part as minute threads which pursue winding courses through 
the small pores of the rock. A large proportion of the water enters 
by percolation through the soil, but locally considerable quantities 
pass directly to the underground channels through sink holes. Thus, 
much of the water which enters the earth as sinking streams or by 
percolation from the lakes which occupy sink holes is added to the 
underground streams. This fact has an important bearing on the 
potability of the underground water, because sink holes are often 
filled with refuse which may contaminate the water and render it 
unfit for use. 

Over a large part of the central portion of the peninsula, the under- 
ground waters of the limestones of the Vicksburg group lie several 



UNDERGEOUND WATERS OP CENTRA!. AND NORTHERN FLORIDA. 249 

feet below the surface of the ground. The upper limit of the saturated 
zone forms a comparatively flat water table which, according to 
Sellards ^ (see figs. 2 and 3, p. 224) bears little resemblance to the sur- 
face topography. Similar conditions prevail in the portion of the State 
lying north of a line passing from Duncan northeastward to Apa- 
lachicola River, and near the west coast from Wakulla County south- 
ward nearly to Pasco County. 

WATER IN THE CHATTAHOOCHEE FORMATION. 

The Chattahoochee formation is commonly a close-grained lime- 
stone or marl, which, although porous, will in places yield only a 
small quantity of water. This is due to the fact that in much of it 
the water occupies small openings where it is held with great tenacity. 
Nevertheless the Chattahoochee formation usually furnishes ample 
supplies for farm and domestic uses. Where large supplies are 
obtained the water is commonly found in what the driller regards as 
a cavity, some of which, however, are really well-defined channels 
in the limestone through which streams flow. The supply of water 
is governed by the size of the underground stream, many wells being 
drilled until two or more channels have been cut. The topography of 
the region where the Chattahoochee formation is near the surface is 
characterized by numerous sink holes, which bear testimony to the 
existence of many underground channels of considerable size. 

The water obtained from the Chattahoochee formation is generally 
considered to be of good quality. It usually contains more or less 
lime, magnesia, and other mineral substances common in limestone 
waters. Rarely it contains some hydrogen sulphide gas, and in 
such cases it resembles water from the limestones of the Vicksburg 
group. In general limestone waters, when obtained from under- 
ground streams, are more likely to be impure than waters from 
sandstone. Moreover, there is a much better opportunity for natural 
purification in sandstone than in limestone. 

WATER IN THE HAWTH6RN FORMATION. 

The Hawthorn formation contains sand, clay, and limestone, and 
each of these materials will supply more or less water. The clay is 
not an important water-bearing bed because, though it contains a 
great deal of moisture, the supply available for weUs and springs is 
very small. The limestones are similar in character to those of the 
Chattahoochee formation but are more broken and phosphatic and 
contain many pores and crevices which will hold water. The sands 
are important water-bearing beds, furnishing water for both wells and 
springs. They are usually so thin that the water supply is not large, 

1 Sellards, E. H., Preliminary report on the underground water supply of central Florida: Bull. 
Florida State Geol. Survey No. 1, 1908, p. 32. 



250 GEOLOGY AND GROUND WATERS OF FLORIDA. 

but it is fairly constant in amount. Owing to the impurities in these 
sands the water derived from them is apt to be hard and to contain 
the same sort of mineral matter that is found in the limestone waters 
of the Hawthorn and Chattahoochee formations. 

WATER IN THE TAMPA FORMATION. 

The Tampa formation consists of hmestones and clays; the former, 
being more or less porous in places, yield considerable water; the 
latter contain large quantities but yield little either to wells or 
springs. The limestones are separated by a layer of chert, sometimes 
known as the "Tampa silex bed,'' which is dense and relatively imper- 
vious, so that it prevents the rapid escape of moisture. The best 
water bed in the formation is that portion of the upper limestone 
which hes just above the chert. Aside from the water distributed 
through the hmestone of the Tampa formation more or less water is 
present in the form of well-defined underground streams, similar to 
those which exist in the Chattahoochee formation. The quahty of 
the water is much the same as that of the Chattahoochee formation, 
the mineral substances present being lime, magnesia, etc., and the 
water being as hard. 

WATER IN THE ALUM BLUFF FORMATION. 

The Alum Bluff formation ranges in composition from pure sand to 
pure clays and fuller's earth, but by far the most common material is 
a sand containing some clay or Ume. The presence of marl is not 
uncommon, especially near the base and the top of the formation. 
Some nearly pure hmestones are included in this formation, the most 
important being those at Sopchoppy and near EUenton and southwest 
of Lakeland. The shell marls of Chipola River, of Shoal River, and 
of Oak Grove have been given separate names and are regarded as 
members of the Alum Bluff formation. 

With such a varied composition the water-bearing capacities of the 
several members of the Alum Bluff formation necessarily differ. In 
general the formation contains an abundance of water, which occurs 
in the pores of the materials. The supphes are large in both sands 
and clays, though the wells that penetrate the sands yield better than 
those that enter the clays. Though comparatively thin this forma- 
tion is widely distributed and is the source of supply of many wells 
in north-central Florida. 

The composition of the water from the Alum Bluff formation varies 
with the nature of the material from which it is obtained, grading 
from the pure soft water of the sands to the hard lime and magnesia 
bearing water of the marls. The clays commonly supply hard water 



UNDEKGROUND WATERS OF CENTRAL AND NORTHERN FLORIDA. 251 

because they contain more or less carbonate of lime and other soluble 
mineral matter which is taken up as the water percolates through the 
small passages. Moreover, the water moves slowly through the clays, 
and hence is kept for a long time in close contact with the soluble 
mineral substances which they contain. 

WATER IN THE MIOCENE SERIES. 
CHARACTER. 

The Miocene rocks of Florida contain far less important water- 
bearing beds than the Oligocene. The reasons for this are to be 
found chiefly in the diminished porosity of the younger rocks and 
their slight thickness and small areal distribution. With the increase 
of clay the openings which yield water are reduced both in size and 
number, and hence the Miocene marls and Hmestones, which contain 
considerable proportions of such material, are only moderately good 
sources of imderground water. However, many of the shallow wells 
in the area where Miocene rocks are near the surface draw their sup- 
plies from the beds of this age. 

WATER IN THE JACKSONVILLE FORMATION. 

The Jacksonville formation contains several different kinds of 
rock, the most important being sand and clay arranged in alternating 
beds of moderate thickness. Limestones occur at numerous horizons, 
but most of them are impure and of small thickness. The principal 
water-bearing rocks of the formation are the sands and limestones. 
The clays are of little or no importance as aquifers, because they are 
too fine grained to yield water to wells and springs. Both the lime- 
stones and sands of this formation are impure, but they are sufficiently 
porous to permit the absorption and storage of considerable quantities 
of water, which they readily yield to both wells and springs. 

The Jacksonville as a whole is of little importance except for 
shallow wells. Few deep wells obtain large supplies from it, and 
most wells penetrating it are continued to the excellent water-bearing 
limestones of the Vicksburg group. The limestones belonging to the 
Jacksonville formation yield hard water, but the sands in many 
places supply water which is practically free from mineral matter and 
is therefore regarded as soft. 

WATER IN THE CHOCTAWHATCHEE MARL. 

The waters of the Choctawhatchee marl have not been extensively 
exploited because the marl is usually a poorer water bearer than the 
underlying Alum Bluff formation or the overlying Pleistocene, but 



252 GEOLOGY AISTD GKOUND WATERS OF FLORIDA. 

the marl supplies water to a few shallow wells and to numerous small 
springs. Only dug wells are large enough to afford enough surface 
for the entrance of water by soil seepage. The springs are commonly 
small, indeed they often represent mere seepage at the head of some 
raviae. The reason for the meagerness of the supplies is to be found 
in the close-grained character of the material, which causes it to 
hold water with considerable tenacity. The water is usually hard 
and bears a strong resemblance to that derived from the older lime- 
stones, though it is practically free from hydrogen sulphide and other 
gases which are common in some of the waters from the Vicksburgian 
limestones. 

WATER IN THE PLIOCENE SERIES. 
GENERAL CONDITIONS. 

The hydrology of the Pliocene presents no exceptional features. 
The conditions closely resemble those found in the Miocene except 
that the Pliocene in many places contains a very high percentage of 
clay. This is particularly true of the Lafayette ( ?) formation, which 
forms the upland cover of considerable areas and is penetrated by 
many wells. The local differences in the Pliocene deposits have 
given rise to different hydrologic conditions, so that the rocks of the 
PHocene may furnish much water in one locality and little in another. 

WATER IN THE NASHUA AND CALOOSAHATCHEE MARLS, 

The Nashua and Caloosahatchee marls are sandy shell marls which 
should yield considerable water, but their thickness is seldom great 
and they are not important water bearers, though where not too 
deeply buried they should prove valuable as sources of supply for 
shallow wells. At present the region underlain by the Pliocene marls 
is thinly settled and most of the wells reach water-bearing beds in 
the older rocks. The quality of the water from the Pliocene marls 
has not been determined, but the nature of the materials leaves little 
doubt that the water is hard. 

WATER IN THE ALACHUA CLAY. 

The Alachua clay is a thin deposit which occurs in more or less 
isolated patches. The sandy clays comprising the formation are 
sufficiently porous to absorb a large quantity of water, but they 
hold it so firmly in the minute openings between the grains of the 
clay that but little of it is available for wells. Owing to the fact 
that the formation occurs as discontinuous patches of slight thickness 
it is of practically no importance as a source of water. 



UNDEEGROUND WATERS OF C^INTRAL AND NORTHERN FLORIDA. 253 

WATER IN THE BONE VALLEY GRAVEL. 

The Bone Valley gravel consists of uncemented sand and phos- 
phatic or qiiartzitic pebbles, in many places embedded in a matrix 
of marl or clay". The materials are sufficiently porous to yield moder- 
ate quantities of water for shallow wells. The region in which the 
formation is developed is characterized by deep wells sunk to sup- 
ply phosphate mines, and hence little demand is made on the water 
in the gravel. The Bone Valley gravel is reported to supply moder- 
ately hard water, suitable for ordinary domestic and farm uses. 

PLIOCENE (?) SERIES. 

WATER IN THE LAFAYETTE (?) FORMATION, 

The Lafayette ( ?) contains a large percentage of clay and is locally 
a poor water-bearing formation. However, sand lenses and beds 
hold some water which is readily available to shallow wells. The for- 
mation is the source of many excellent springs, though few of them 
are large. Apparently the water enters porous sands and sinks until 
it encounters relatively impervious clay. The springs occur where 
the impervious bed reaches the surface, which may be either on a 
slope or in a ravine. The erosion and redeposition of material has 
produced many porous sands which contain large quantities of water, 
but these sands are mostly of Pleistocene age. 

The water from the Lafayette ( ?) formation varies greatly in the 
amount and character of its dissolved mineral matter. Some of it is 
soft, but in springs and shallow wells moderately hard water is com- 
mon. In general the water from the Lafayette (?) formation is 
thought to contain less mineral matter than the water from some of 
the limestone beds, but this opinion lacks verification because of the 
lack of chemical analyses for comparison. The general opinion that 
the water contains iron is probably correct, though here again analyti- 
cal evidence is lacking. 

PLEISTOCENE AND RECENT SERIES. 

The Quaternary formations are important locally as sources of 
underground water but are in general too thin to contain much water. 
Practically all Quaternary deposits of any considerable importance 
as sources of water belong to the Pleistocene. Locally, the Pleis- 
tocene beds attain a thickness of 50 to 100 feet or more, and in such 
places they usually yield abundant supplies to wells. Where the 
Pleistocene beds are too thin to yield much water they may serve 
a valuable hydrologic purpose by absorbing it. Their materials are 
open and porous and the passages between the separate grains are 



254 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

large enough to permit the absorbed water to sink rapidly, thus pre- 
venting early saturation of the surface layers, followed by excessive 
run-off. 

The water from the Quaternary beds is usually soft, though the 
presence of marl and coquina at some localities should permit the 
solution of calcium carbonate and other constituents such as occur 
in these materials. Hard water may be expected in. the Pleistocene 
of the coastal region where marls and limestones are found. Such 
waters are common in the northern part of the State, where many 
Pleistocene beds contain calcareous material derived from the ero- 
sion of the older rocks. 

The redeposited materials from the Lafayette ( ?) formation occupy 
the slope and terraces of the valleys of the northern part of the State, 
where they supply abundant water to many springs and shallow 
wells. These supplies may usually be distinguished from those of 
the other Pleistocene deposits by their larger content of mineral 
matter, which renders the water hard. 

In the vicinity of Kissimmee flowing wells are obtained from 
sands which are probably of Pleistocene age, though some of them 
may be Pliocene. Examples are to be seen in the shallower wells 
of the Lee-Parsons Cattle Co. and in some other shallow flowing 
wells near Kissimmee. In west Florida flowing wells from beds 
that may be of Pleistocene or of late Tertiary age are obtained on 
the shores of Pensacola Bay and as far eastward as Apalachicola. 
Most of these weUs are confined to the low land near the coast and 
few yield abundantly. The water is commonly softer than that 
obtained by flowing wells from the Vicksburgian limestones, but it 
usually contains considerable hydrogen sulphide gas, doubtless 
derived from decaying organic matter scattered through the water- 
bearing sands. 

PUBLIC WATER SUPPLIES. 

The accompanying table gives the statistics of public water sup- 
plies of towns and cities in central and northern Florida. 



DeLancfomwell. 

Orange ( 
Seville a 

w. 

Freeport 

De Funi 

■WAS! 

Chipley 
Vernon . 



Public water supplie 



I <mtl northern Florida. 






Beach-Rogere Lumber ' 



Pumped from well.. 



T&'!' 



S,«.™' 



S^vsfomboing installed. 
Sv.n'inbefnginstaUed. " 



Hard and sulphui 



Sufllcleni 



GEOLOGY AND GKOUND WATERS OF FLORIDA. 255 



SURFACE AND UNDERGROUND WATERS OF SOUTHERN 

FLORIDA. 

By Samuel Sanford. 

SOURCE. 

Most of the water from shallow wells or from springs in southern 
Florida represents rain that fell at no great distance. Although the 
surficial limestones contain many solution cavities, and although 
circulation through these is comparatively free, yet the general ele- 
vation of the surface is so slight that long travel underground is pre- 
sumably exceptional. Most of the rain that falls in the Everglades 
and most of the water that flows into them from Lake Okechobee is 
evaporated or reaches the sea or the GuK by creeks and rivers, the 
part escaping underground being small — much smaller than the 
statements of some writers would indicate. Its unimportance is 
shown by the absence of springs of fresh water along great stretches 
of coast and by the many wells which have found salt water at shallow 
depths. The elevation of the Everglades is so slight and the lime- 
stones are so widely covered by marls and sands that direct under- 
ground transfer from the swamp to the ocean or the Gulf is difficult. 

The deep waters under relatively high heads reached by the wells 
at Gomez, Hobe Sound, and Palm Beach on the east coast, and those 
at Marco and points northward on the west coast evidently do not 
come from the Everglades. They need a much higher source, and 
are suppHed from beds containing water that owes its pressure to 
rainfall on the ridge of highland along the west side of the peninsula 
north of Lake Okechobee. (See p. 259.) 

WATER TABLE. 

. Except under dunes, the higher portions of the sand plains, and 
the more elevated rock ridges, which form an insignificant portion of 
the total land surface of southern Florida, the water table everywhere 
lies close to the surface and rises above it over many hundred square 
miles during late summer and early fall. Because of the generally 
low elevation of the land and the extent of the nearly flat areas the 
upper surface of the ground water has little movement except in 
narrow areas near the coast. The water table is everywhere nearly 
flat. In the limestone, owing to the many free passages, it is even 
flatter than it is in the sands. 

The rise and fall of the water table respond to the seasonal fluctua- 
tions of the rainfall, the amplitude of the yearly swing varying with 
the annual precipitation and the difference in rainfall between the 
wet and dry months of any given year. Also it is dependent to a 
certain degree on the geology and topography, being less in open- 
76354°— WSP 319—13 17 



256 GEOLOGY AND GROUND WATERS OF FLORIDA. 

textured beds near the coast or stream channels than in fine deposits 
away from points of outflow. " 

Besides rainfall fluctuations other causes (pp. 224-225) affect the 
level of the ground water. Near the coast the most potent is the rise 
and fall of the tide, and particularly the periodic groups of maximum 
and minimum tides. At many shallow wells along the coast, includ- 
ing those not affected by direct infiltration of sea water, there is a 
perceptible rise and fall of water level that lags after the times of 
high and low tide, the lag being determined by the porosity of the 
water bed and the distance of the well from the shore line. Dr. Bessey, 
director of the Sub-Tropical Experiment Station, near Miami, stated 
that in a shallow well in the grounds of the station a few rods from 
the shore of Biscayne Bay, the time-amplitude curve of the height 
of the water in the well was much more abrupt on the rise than on 
the ebb. This variation probably is due in large measure to out- 
flowing ground water and resembles the tidal curves of many surface 
streams. The writer observed the tidal lag of the water in pits and 
wells on Key Vaca and Big Pine Key but, as Was to be expected from 
the small area of the keys, found no such regular variation of level as 
Bessey found at Miami. 

Along the keys the fluctuations due to tides are naturally more 
marked than on the mainland. The tidal variations of the well 
water at Key West were noted by Tuomey. The rise of salt water 
in potholes and swamps along the keys, through underground pas- 
sages, is a most striking feature of the semiannual periods of maxi- 
mum high tides. 

SPRINGS. 

No such giant springs as are found in the central and northern 
parts of the State are known in southern Florida, and, indeed, springs 
of any size, except near Biscayne Bay, are rare. The reasons for this 
are obvious. The surface has slight elevation, hence underground 
circulation can not be vigorous. The Pleistocene limestones are 
readily dissolved and are full of solution passages, but few of these 
openings extend 20 feet below the surface, and the underground 
circulation is local rather than regional. Only in the Biscayne pine 
land have the rock ridges sufficient height to give the underground 
water a chance to erode connecting passages and gather water. 

In southern Florida the OHgocene limestones, which are the great 
source of the giant springs of the region to the north, are deeply 
buried by sands and sandy marls, so that any water contained ia 
them in large passages or openings must cross the bedding of many 
hundreds of feet of soft material contaiaiag clayey layers to reach the 
surface. 

Springs of some size occur along the east coast, the largest flowing 
from the low ridges of Miami oolite near Biscayne Bay. Reports of 



SURFACE AND UNDERGROUND WATERS OF SOUTHERN FLORIDA. 257 

giant springs under the ocean, thougli common, are difficult to verify. 
The writer does not know of such springs and is incUned to take 
reports regarding them with much reserve. Necessarily they would 
have their source in hmestones buried under 800 feet or more of 
sediment, chiefly loose sands, and any water rising through these 
sands would escape as small seeps rather than bold flows and would 
mingle with the salt water in the beds before reaching the sea floor. 

There are no true springs so far as known anywhere along the keys, 
though reports of such are even more plentiful than of big springs 
under the ocean north of Miami. It is not difficult to find fishermen 
who say they have seen water flowing from the sea bottom at such 
and such a place along the keys, and springs are frequently reported 
from Big Pine Key and Key West. An offer of a reward for the find- 
ing of a spring of fresh water on the keys or the adjacent sea bottom, 
however, secured no takers. The so-called springs on the keys are 
natural wells yielding more or less brackish water under no more head 
than that due to the rise of the water table from local rains, the rise 
and fall of the tides, and barometric fluctuations. The elevation of 
the keys is slight; their honeycombed hmestones can not confine 
water, and surface springs, though possible after heavy rains, ob- 
viously can not be permanent. 

Alongshore on the west coast springs are rare, as is to be expected 
from the slight elevation of the land, the thinness of the surficial 
hmestones and the mantles of sand and marl extending below sea 
level. There are no springs of note between Cape Sable and Big 
Marco Pass. Vessels obtain water along this stretch of coast from a 
few shallow wells in beach ridges or from cisterns. 

The cavernous or, rather, the honeycombed character of the 
Miami oohte in the Biscayne pineland about the margin of the 
southern Everglades, and on Long Key and its neighboring keys, and 
the many small sinks or potholes are the apparent basis for the 
reports of big springs in the Everglades. That there are springs 
just outside the eastern margin of the Everglades is well known; 
there is one, for instance, in Miami River just below the rapids from 
the pool back of the rock rim of the Everglades; but the existence of 
true springs in the main body of the saw grass, away from dry land, 
seems more than doubtful. 

In times of high water there may be perceptible currents flowing 
from some of the potholes and natural wells near sloughs and rivers, 
but at such times it is difficult to separate surface from underground 
circulation ; the Hmestone is full of holes and there is in places a suffi- 
cient gradient toward the watercourses for water to move freely 
underground. In times of low water, with the water in rock openings 
standing below the surface of the adjacent parts of the Everglades, 
the case is quite different. Out in the saw grass, where the water 



258 GEOLOGY AND GEOUND WATEKS OF FLOKIDA. 

surface is nearly level, where there is no high ground near to supply- 
shallow water under head, true springs of large size would seem to be 
Hmited to those that might come from the deeply buried limestones, 
and the thick cover of sand and marl makes negligible any possi- 
bihty of bold flows from that source. 

WATER-BEARING FORMATIONS. 

OLIGOCENE SERIES. 

Some of the geologic formations named in the description of the 
geology of southern Florida (pp. 167-199) are decidedly important 
water bearers, others are practically of no account, but no single forma- 
tion yields potable water under the whole extent of the mainland. 

Of the Ohgocene limestones the Vicksburg group, the most notable 
and economically important water bearer in Florida, supplies a few 
wells on the east coast, which yield strong flows of saUne sulphureted 
water that is too highly mineralized for general domestic use or for 
boiler supply. No well has reached these limestones on the east 
coast south of Palm Beach, and the only wells to reach them south of 
the mainland are at Key West and possibly at Knights Key. On the 
west coast the Vicksburgian limestone supphes many fine flowing 
wells in Lee County, particularly in and near Fort Myers. The 
waters there are decidedly less mineralized than on the east coast. 

MIOCENE AND PLIOCENE SERIES. 

The sands and sandy marls of Miocene and Phocene age that form 
so large a part of the sections shown by deep wells on the east coast 
and along the keys are of sHght consequence as sources of water 
supply. Though they are filled with water they do not yield it so 
freely to wells as do the Vicksburgian hmestones. On the east coast 
no flows of consequence were found in the Miocene and Pliocene beds. 
On the west coast from Estero north a few wells find small flows of 
good water in the Miocene beds. 

PLEISTOCENE SERIES. 

As they lie near surface on the mainland of southern Florida and 
on the keys and have a possible maximum thickness of 125 feet, the 
Pleistocene beds are the sources of springs and the great reservoirs for 
shallow wells. They have been extensively developed, but can 
supply many times the amount of water now drawn from them. The 
quality of their waters varies decidedly. Wells in limestone yield 
supphes high in calcium and bicarbonate; many wells in the sands 
of the dunes and of the rolling sand plains yield water that is soft and 
of low miner aUzation. Because the waters lie near the surface they, 
particularly the limestone waters, are liable to pollution by privies, 
hogpens, and slop holes, and more care than is commonly taken 
should be exercised in locating and protecting wells. 



SUKFACE AND UNDEKGROUND WATERS OF SOUTHERN FLORIDA. 259 

ARTESIAN WATER. 

The factors that determine the presence of artesian water have 
already been discussed (pp. 234-235), but the extent of the area in 
southern Florida that is underlain by beds containing artesian water 
and the probable character of the artesian supplies are questions 
that merit consideration. 

There is no area of high ground in southern Florida, and the 
larger part of the surface is less than 22 feet above sea level; hence 
the only possible source for flows with heads of over 30 feet, as those 
at Marco on the west coast, and Palm Beach on the east, is the high 
ground west* and north of Lake Okechobee. This high ground is much 
nearer the west coast than the east and very much nearer the east 
coast than the southern end of the peninsula. Hence, conditions of 
porosity of water bed, slope, and tightness of cover being the same, 
higher heads, stronger flows, and better water are to be expected on 
the west coast than on the east, and lower heads and poorer water 
toward the south. Just how far south along the east coast or the 
west coast flowing wells can be had is somewhat conjectural, but it 
is safe to say from what is known of the topography and geology 
that deep wells can get water that will flow at the surface; that is, 
rise to 22 feet above tide, throughout Lee and Palm Beach counties 
and the northwestern part of Dade County, or in a region north- 
west of a line drawn from Hillsboro Inlet to Pavilion Key. It is 
possible that water rising above sea level can be had as far south as 
Miami by wells 1,000 feet deep. The prognosis for quality is far less 
promising than that for strength of flow. The reported salinity of 
the water in the wells near the Devils Garden, west of the Everglades, 
and the high mineralization of the flows at Marco and Palm Beach 
offer little hope for flows of good potable or industrially valuable 
water from deeply buried beds at points near the shore anywhere 
around the southern end of the peninsula from Palm Beach to Naples. 

QUALITY OF WATER. 

The surface water of the Everglades and its connected sloughs and 
swamps is commonly clear but highly colored and is lower in mineral 
content than that of most wells in the region. This is contrary to 
the frequently expressed belief that such water is charged with cal- 
cium salts. Some small lakes in the rolling sand plains and among 
the ridges of the dunes east of the Everglades, occasionally connected 
with it by temporary arms across the flatlands, contain softer water 
than that of the Everglades. 

The shallow limestones yield calcium bicarbonate waters of mod- 
erate mineral content except where contaminated by salt water. 
The normal supplies are used for domestic purposes, but for steam- 
ing they are rather high in scale-forming ingredients, and boiler 
compounds for softening them are consequently in common use. 



260 



GEOLOGY AND GKOUND WATERS OF FLORIDA. 



Many waters from the sands are low in total solids and good for 
domestic use or for boiler supply, though some are hard enough to 
necessitate softening. 

The supplies from the Vicksburgian limestones on the east coast 
are salt, hard, sulphur waters of high mineral content. They are 
little used except for irrigating crops resistant to saline solutions. 
The deep waters of the west coast are similar in composition; some 
of them, like those at Fort Myers and at other places in Lee County, 
are used for domestic and industrial purposes, though they are more 
likely than the shallow waters to form hard scale and to be corrosive 
in boilers. Others are too salty for any use except bathifig or closet- 
flushing. It is important to note that only strong salt water has 
been drawn from deep borings on the keys. Many wells in limestone 
along the mainland shore, however, also are affected by salt water. 

Assays by the writer of some waters from wells in southern Florida 
are given in the following table: 

Assays of water from wells in southern Florida. o- 
[Parts per million unless otherwise designated.] 



Location. 


Depth. 


Odor. 


Carbon- 
ate 
radicle 
(CO3). 


Bicar- 
bonate 
radicle 
(HCO3). 


Sulphate 
radicle 
(SO,). 


Chlorine 
(CI). 


Total 
hard- 
nesses 
CaCOa. 


DADE COUNTY. 

Key 


Feet. 
28 

90-98 
18 
20 


None .. 


0.0 


200 
240 
370 
220 
190 

180 
135 
150 
165 
165 
110 
175 
140 

180 
250 
180 
210 


30- 
100? 

30- 
200+ 

30- 

200+ 
215+ 
190+ 
190 
180+ 
30- 
125 
240+ 

90 
60 

870 


20 
3,300 

50 
2,200 

50 

650 
900 
4,000 
800 
1,100 
1,500 
1,100 
1,700 

600 
400 
400 
65 
17,000 
18,000 
19,000 
19,000 
22,000 
22,000 
22,000 
22,000 
22,000 
22,000 
22,000 
22,000 
21,000 
26,000 

15 
25 


235 


Miami 


220 


Do 




.0 
.0 
.0 

.0 

Tr. 

.0 


350 


Do 




310 


Do 




235 


LEE COUNTY. 

Buck Key 


605 
960 
460 
140 
232 
134 
344 
420 

3 

3 

6 

6 

38 

60 

80 

116 

140 

168 

178 

210 

240 

276 

308 

370 

400 

495 

52 
26 


HjS 

H2S 

H2S 


290 


Fort Myers 


+300 




400 


Punta Rasa 




Do 


H2S 

H2S 

H2S 

H2S 


.0 

.0 

Tr. 

0. 

.0 
.0 
.0 
.0 




St. James City 


600 


Do 




Sanibel Island 




MONROE COUNTY. 

Big Pine Key 




Do 






Do 


Vegetable. 


210 


Cape Sable 


230 


Marathon 








Do 












Do 




.0 
.0 


150 
180 
160 






Do 








Do 








Do 


H2S 








Do 






170 
190 
160 
220 
170 
140 
160 
150 

20 
24 






Do 










Do 










Do 


H2S . . 








Do 


None 








Do 










Do 


None 


.0 






Do 






PALM BEACH COUNTY. 

Hobe Sound 


None 

...do 


.0 
.0 


30- 
30- 


80 


Jupiter 


85 







o Assays performed by Samuel Sanford according to methods outlined in Water-Supply Paper U. S. 
Geol. Survey No. 151, 1905. 



SURFACE AND UNDERGROUN^D WATERS OF SOUTHERI^ FLORIDA. 261 

These assays show that the waters sampled are generally hard, that 
the hardness of the shallow waters is due to bicarbonate of lime, and 
that of the deep waters to bicarbonate and sulphate of lime, that the 
saltness (chlorine content) varies widely, and that at Marathon, on 
Key Vaca, all the water to a depth of nearly 500 feet is as salt as sea 
water. 

RELATIONS OF FRESH AND SALT WATER UNDERGROUND. 

Many of the conditions governing the occurrence of salt water in 
underground strata are not known at present, but some features of 
these phenomena, which are of the utmost economic importance in 
southern Florida, are explainable by the data obtained during this 
investigation. 

The shallow salt waters found along the keys and at different 
places on the mainland of southern Florida are due to direct penetra- 
tion of sea water into the underground strata, which commonly 
throughout this region are limestones full of seams and crevices that 
permit easy entrance of surface water. The keys, where the limestones 
are full of openings, may be completely underlain by salt water 
at about tide level; this is the condition on islands as wide as 3 
or 4 miles in the Bermudas and also on many Florida keys. Where 
porous beds form the sea floor along the mainland coast salt water 
may likewise displace fresh water for some distance inland. Fresh 
water, percolating through the surface sands or passing through rock 
channels directly to the salt-water level, moves seaward above the 
saline solution by reason of its superior position and its lower spe- 
cific gravity, but it also has a tendency to mix with the salt water 
through diffusion. Under these conditions the thinner the fresh- water 
sheet the less its seaward gradient, and the freer the underground circu- 
lation the greater is the admixture of salt with fresh water. Therefore, 
the chances of finding potable water are better in the sands of beach 
ridges and on sandy islets than in the open-textured limestones on 
the keys or near the coast of the mainland. 

The deep salt waters of southern Florida may represent original 
sea water that was contained in the beds when they were deposited 
and has not been removed, or secondary sea water that penetrated 
beds containing fresh water during the depression of the land, or 
water originally fresh that has become saline by traversing salt- 
bearing formations. Such formations are of different ages, from 
Oligocene to late Miocene or early Pliocene, and range in texture 
from limestones containing open passages to fine-textured sand- 
stones and marls; and as they are found not only on islands but 
also at some distance inland it is unlikely that any one of the above- 
mentioned causes of salinity applies to all of them. 



262 GEOLOGY AND GBOtTlTD WATERS OF ELOBIDA. 

Except for deposits lying on or near the surface the materials from] 
which the southern part of the State were constructed are of marine 
origin and once contained salt water. That large areas of these 
deposits do not now contain salt water for several hundred feet below | 
sea level is evidence of an uplift sufficient to give fresh water active 
circulation to considerable depths. (See pp. 207-209.) During such 
uplifts and subsequent depressions saline material must have been 
leached from the marine beds under great areas by fresh water and 
the latter in turn displaced by sea water; changes from salt to fresh 
and to salt water again may have taken place several times. Con- 
sequently it is possible that none of the salinity now found on the 
mainland or the keys in, for instance, the Vicksburgian limestones, 
represent original sea water. Deeply buried beds are more Ukely to 
contain original sea water near the present shore line than inland and 
near areas of high land than in areas remote from high land. Simi- 
larly, deep-lying secondary salt water may occur under large areas of 
low ground rather than under high land and near the shore rather 
than inland. 

Whether any given sahne water represents original sea water, sec- 
ondary influxes, or supphes that have acquired salt from the beds 
they have traversed is a question of some interest; and if the cliar- 
acter of the water-bearing beds, their geologic history, and the chemi- 
cal composition of their water were known it could be answered with 
some exactness. The decided differences in chemical composition 
and in concentration indicate diversity in derivation of salinity. 
Most salty flows in southern Florida do not resemble sea water in 
composition, for they are high in carbonates and low in sulphates and 
magnesium, whereas sea water is characterized by high sulphates, 
low carbonates, and magnesium in excess of calcium. The peninsula 
has evidently been raised above and depressed below its present 
level with resulting modification of underground circulation, and the 
salinity of the deep waters is probably due to secondary influxes dur- 
ing the last marked depression. 



PART IV.— COUNTY DESCRIPTIONS. 

ALACHUA COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Alachua County lies in the north-central part of the peninsula on 
the drainage divide between the Atlantic Ocean and the Gulf of 
Mexico. It comprises a portion of the upland known as the lake 
region, from the large number of lakes which apparently occupy 
depressions in the underlying limestones. The surface of the county 
consists of rolling pineland interspersed with level uplands and flat, 
marshy lowlands. A large depression south of Gainesville, formerly 
occupied by a lake, is now; drained and is known as Paynes Prairie. 
The water entering this basin passes to an underground channel 
through an open hole known as Alachua sink. Many other sink holes 
exist in different parts of the county, an especially interesting one 
being the Devils Mills Hopper, northwest of Gainesville, with a diam- 
eter of a few hundred yards and a depth of over 100 feet. It receives 
the drainage of springs and commonly contains a small quantity of 
water which gradually escapes to an underground stream. A sink 
south of the town of Alachua aifords entrance to the cavern known 
as Warrens Cave, which is reported to be accessible for more than a 
mile from the opening. 

GEOLOGY. 

The surface deposits of Alachua County consist of gray sands under- 
lain by older rocks of differing composition. Sands lying below the 
100-foot contour were probably deposited in lakes or in shallow 
marine waters, but those lying above that contour are largely residual 
products left by the decomposition of older geologic formations. The 
Alachua clay occurs in the form of small and unimportant patches 
of bluish sandy clay lying in depressions in the underlying rocks. 
The Alum Bluff and Hawthorn formations are well developed in 
the northern half of the county, where they consist of sands, clays, 
and limestones, the latter largely cherty and in places more or less 
phosphatic. Smaller areas of these formations rest on the Vicksburgian 
Hmestones in the southern part of the county, where they form more 
or less discontinuous patches or ridges. The Vicksburgian lime- 
stones underlie the entire surface of the county, but they are usually 
covered by other formations or by residual sands of the younger 
formations. 

263 



264 



GEOLOGY AND GROUND WATERS OF FLORIDA. 



The surficial sands in few places exceed 50 feet in thickness, though] 
locally they may be somewhat thicker; they average probably less 
than 30 feet. The Alum Blaff and Hawthorn formations and the! 
Alachua clay are generally thin, though locally the Hawthorn forma- 
tion may exceed 100 feet. A thickness of several hundred feet hasj 
been assigned to the Vicksburgian limestones, but the exact amountj 
is not known because the deepest wells terminate in rocks that appear! 
to be of this age. From samples obtained in drilling wells it has been! 
possible to construct the sections given below, and, though some of 
the correlations are more or less uncertain, the descriptions show 
the general character of the rocks penetrated. 

Log of the well of Diamond Ice Co. at Alachua. 



Thickness. 


Depth. 


Feet. 


Feet. 


7 


7 


15 


22 


58 


80 


100 


180 


20 


220 


50 


270 



Sand, brown 

Clay, soft, brown 

Limestone, soft, white 

Limestone, hard, gray 

Limestone, hard, bro\vnish white 

Limestone, hard, gray, eontaiaiag layers of blue flint 



Water-bearing beds were encountered between 50 and 120 feet 
and between 250 and 270 feet. The beds from 1 to 22 feet appear 
to be residual. The limestones of the Vicksburg group were encoun- 
tered at 22 feet and continued to the bottom of the well. 

Log of the well of C. E. Milton at Micanopy. 



Not recorded 

Loam, dark gray, sandy 

Sand, dark gray; partly consolidated 

Sand, orange yellow 

Sand, gray; containing small percentage of clay 

Sand, gray ; contatauig some clay with yellow streaks due to the presence of iron oxide. 

Sand, light yellow, and clay 

Clay, light gray to white; containing some sand 

Sand, white 

Clay, light green, sandy 

Clay, light gray to yellow, sandy 

Clay, light gray 

Clay, light green ; with a little sand 

Clay, hard, light gray; with very little sand 

Marl, light gray to greenish 

Limestone, brownish gray; containing some sandy clay 

Clay, fine grained, light gray, and limestone 

Limestone, light gray to white 

Limestone, soft, white 

Limestone, white, chalky 

Limestone, light graj^; containing fossils... — 

Limestone, white; with few fossils 



Thickness. 


Depth. 


Feet. 


Feet. 


1 


1 


2 


3 


3 


6 


5 


11 


4 


15 


2 


17 


18 


35 


s 


37^ 


1 


40 


8 


48 


1 


49 


3 


52 


3 


55 


12 


67 


4 


71 


4 


75 


14 


89 


7 


96 


5 


101 


49 


150 


i 


150i 



The material from 1 to 6 feet may be Pleistocene sand, and that] 
from 6 to 17 feet may be Alachua clay, or a portion of the upper] 
Oligocene. The beds between 17 and 52 feet probably represent the} 



ALACHUA COUNTY. 265 

Hawthorn formation. Limestone of the Vicksburg group appears to 
have been encountered at about 52 feet. Characteristic Vicksburgian 
fossils were obtained between 89 and 150 J feet. 



Log of well ofF.P. Henderson at Arno. 








Thickness. 


Depth. 


Unrecorded . 


Feet. 

55 

5 

6 

6 


Feet. 
65 




60 


Chert, bluish gray; mixed with some sand 


74 




82 







The samples from this well are incomplete. Apparently the Vicks- 
burgian limestones were encountered at less than 55 feet and they 
continued to the bottom of the well. 

WATER SUPPLY. 

Source. — The surficial sands, the Alum Bluff formation, and the 
Hawthorn formation will supply some water, and though the quan- 
tity is seldom large the water level lies near the surface, so that the 
wells may be easily pumped. The Alachua clay contains very little 
water, and this fact, together with the limited distribution of the 
formation, makes it of little value. The Vicksburgian limestones are 
the most important water-bearing formations in Alachua County. 
The depth necessary to secure good supplies from the limestones is in 
few places more than 100 to 150 feet, and locally it is less than 50 feet. 
The Vicksburgian limestones also furnish water for numerous valuable 
springs. 

Quality. — The sands furnish soft water, but the supplies from the 
Hawthorn formation are hard. All the waters obtained from the 
Vicksburgian limestones are hard, but the quantity of inorganic 
material in solution is not great enough seriously to interfere with their 
use for ordiaary purposes. 

Development. — The yield of wells which penetrate the Vicksburgian 
limestones is large and the information at present available appears 
to indicate that the quantity is sufficient to meet all reasonable 
demands. The water level is near enough to the surface to make 
pumping iaexpensive. There is no probability that flowing wells can 
be generally obtained in Alachua County, and hence there is little 
incentive to drill to great depths. Very deep wells would be apt to 
encounter highly mineralized water, unfit for ordinary use, and it is 
doubtful if the head would be materially greater than that of the 
supplies now utilized. The greatest opportunity for improvement is 
in the prevention of pollution, which could be done by using casings 
to exclude surface water from the wells, and by preventing waste 
products from entering water beds through open sinks or drainage 
wells. 



266 



GEOLOGY AND GEOUND WATERS OF FLOKIDA. 



Among the springs large enough to be important is the Boulware 
Spring, which furnishes water for the city of Gainesville, the Poe and 
Magnesia springs at Hawthorn, and the springs at High Springs and 
Traxler. Aside from the springs at Gainesville many of the others 
might be utilized either as sources of water supply or as pleasure or 
health resorts. 

General water resources in Alachua County. 





Topo- 
graphic 
location. 


Source of water. 


Surface 
formation. 


Shallow wells. 


Town. 


Depth. 


Water 
supply. 


Quality of 
water. 


Principal 
water bed. 




Rolling. 

...do 

Level 


Wells 


Clays 


Feet. 










do 

do 


do 

Somie clays. . 




Some.. 


Soft 


Do. 


Arredonda 




Do 


Clark 


Rolling, 
do 


do 

- do 


do 








Do. 


Dutton 


do 








Do 




Hilly 


. . do 


do 








Do. 


G aines ville 


Rolling . 
.do 


Wells and spring 


do . 


Few. 


Fair... 
...do.. 


Partly soft.. 


Do 




xVells 


do 


Do. 


T-lfi'\vtViom 


do 


do 


. do 








Do 


High Springs... 


...do 

...do 




do 








Do. 


Wells 


do 








Do. 


Melrose 


do 


Wells and spring. . 


do 


10-20 
10-35 


Fair... 
...do... 


Partly soft.. 
do 


Do. 




...do... 


Wells 


do 


Do. 


Newberry 


do 


do 


Some sandy 

clays. 
do 


Do 


Rochelle 


Level 


. .do 








Do 


Waldo 


...do 


do 


do 




Fair... 




Do. 





















Deep wells. 


Depth to 
water. 




Town. 


Depth. 


Water 
supply. 


Head 

above 

sea. 


Quality of water. 


Sewerage system. 


Alachua 


Feet. 
216 


Abundant. 
...do 


Feet. 

40-45 
55 
53 


Hard 


Feet. 


None 




do 


40 


Do. 


Arredonda 


125 


...do 

...do 


do 


Do 


Clark 


do 


47 


Do. 


Dutton 




do . . 




do 


Do 


Evinston 


126 

347 


...do 




do 




Do. 


Gainesville 


...do 

...do 


55 


. do 




City system. 


Hague 


do 




Hawthorn 




do 




do 




Do. 


High Springs 




...do 




do 




Do. 


Island Grove 




do 




do 




Do, 


Melrose 




...do 








Do. 


Micanopy 


151 
123 


...do 

...do 

do 


70-75 

35-40 

70 


Hard 




Do. 


Newberry 


do 




Do. 


Rochelle 


. do 


10-15 


Do. 


Waldo 


55 


.. do 


do 


Do. 















Nearest town or 
post oface. 



Alachua. 

Do.. 

Do.. 

Do.. 

Do.. 

Do.. 

Do.. 
Archer.. 

Do.. 

Do.. 

Do.. 

Do.. 

Do.. 

Do.. 
Arno 



Arredonda. 
Clark 



Do. 



Clyatt.. 

Do. 

Do. 
Dutton. 

Do. 



Evinston. 



Gainesville. 



Do 

Do 

Do 

Haile 

High Springs. 

Do 



Melrose... 

Do... 
Micanopy. 

Do.... 

Do.... 

Do.... 



Newberry. 
Do.... 
Do.... 
Do.... 
Do.... 



Do. 

Do. 

Do. 

Do. 
Do. 



Osceola. 



Palmer... 

Do.. 

Rochelle. 

Traxler.. 



Tyler 

Wades 

Wacahoota . 



Do. 
Wilcox. 



Willeford. 



Do.. 

Do.. 

Windsor. 

Do.. 



Directic 
dista 



mile sou 

■Jear.. 



Near.. 
....do. 
I mile sou 
ij- mile soq 
Near.. 



I mile nor - 
^ mile noil- 
2J miles sP 



1 mile we^- 
i mile eas - 



§ mile wes- 
I mile SOU]'* 

1| miles wO 



Near. 



1 mile sou- 

2 miles soi - 
1 mile nor - 
....do....O 



^ mile nor{- 
Near i- 



l mile wea- 
2| miles n<j- 
2^- miles sQ- 
L 
3 blocks s(g 



6 miles nop 
^ mile nor!- ■ 
1 mile nori- ■ 

1 mile we^- • 
6 miles we^ 

2 miles noj- • 



2 miles noP 

I mile sou- - 

I mile norP 
Near i'- 



2 miles nol- 



Near.. 
6 miles no- 
2i miles so 

2| miles so^ 
Near.. 



2 miles no 
4 miles soi 
J mile nor 
i mile sou 



Depth 
to prin- 
cipal 
supply 



Feet. 



106 



50 
50 

120 



194 



150 



119 
110 



123 



100 
140 



54 



Quality of 
water. 



Hard. 
..do.. 
..do.. 
..do.. 
..do.. 
..do.. 
..do.. 
..do.. 



Hard. 



Sulphur. 
Hard.... 



.do. 



Hard 

..do 

..do 



Hard. 

...do.. 
...do. 
...do.. 
...do.. 
...do.. 
...do.. 



Sulphur. 

Soft 

Hard.... 

..do 

..do 

..do 



.do. 



Hard. 



..do.. 
..do.. 



Hard. 
..do.. 
..do.. 
..do.. 



..do 

..do 

Hard, sul- 
phur. 

..do 

Hard 



Soft. 



Hard. 
..do.. 
..do.. 



.do. 



Yield 
per minute, 



Daily. 



Gallons. 



Many. 



Many. 



1,000 



300 



Many. 



800 



Many. 



c 200,000 



120 
200 



Remarks. 



No protective clay. 
Do. 

Protective clay. 
Do. 

No protective clay. 



Incrusts boilers. 
Second supply at 47 
feet. 



Starts in sand. Water 
from Vicksburgian 
limestones. 

Some water below 
principal supply. 



Protective clay. 
Do. 



Incrusts boilers. 



Incrusts boilers, second 
supply at 40 feet. 



Second supply at 37 
feet. 



No protective clay. 



Deepest well in neigh- 
borhood. Starts in 
sand. 



Second supply at 25 
feet. 



Typkal mils in Alachua Counljr. 



,:*„:::::::::::: 


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> W«tot«ipply Paper U. a Qool. Siirrajr No. KB, p. » 



BAKER COUNTY. 

Springs in Alachua County. 



267 



Name. 


Owner. 


Nearest 

town or 

post office. 


Direction and 
distance. 


Discharge 

per 
minute. 


Topographic 
surroundings. 


Use. 


Boulware.. 

Magnesia... 
Poe 


( 
I 


3ity of Gainesville. 
I. C. Brown 


Gainesville. . 

Hawthorn. . 
High Springs 

Melrose 


2 miles southeast.. 
4 miles southwest. . 


Gallons. 
175 

2,500 
44,760 

Small... 


Rolling sandy 
uplands. 
Low, swampy 
Low hum- 
mock. 

do 


City sup- 

^piy. 

Drmkmg. 




3 miles w 
i mile SOX 


est 


Bathing. 


Ford 


] 


5 F Ford 


itheast. . . 


Drinking. 










Name. 


Emergence. 


Improve- 
ments. 


Quality of 
water. 


Tem- 
pera- 
ture. 


Stream. 


Remarks. 




Not boiling.. 
Boiling 

do 


Pumping 
plant. 

All improve- 
ments de- 
cayed. 

Old bath- 


Pa 

So 

I 


rtly soft.. 


°F. 


Enters branch. 
Makes branch . 

Flows into 
Santa Fe 
River. 

Flows into 


Flow varies appreciably. 

Remote from sources of 
contamination. Flow 
does not vary. 

Remote from sources of 


Magnesia 

Poe 


me sul- 
phur. 


73 

72 


Ford 


Small boils.. 


1 

Nc 


louse. 




contamination. Not 
muddy after rain. 
Remote from sources of 










Melrose Lake. 


contamination. 



BAKER COUNTY. 



By G. C. Matson. 



GENERAL FEATURES. 



Baker County lies in the northeastern part of the State and extends 
about 25 miles southward from the Georgia-Florida line. The 
county contains no large streams, but a portion of its eastern bound- 
ary is formed by St. Marys River, and a branch of this stream crosses 
its southern end. Olustee Creek heads in Ocean Pond and flows 
southwestward to Suwannee Kiver. Okefenokee Swamp, which 
occupies a large area in Georgia, extends a short distance across 
the boundary line into Baker County, but with thio exception the 
surface of the county is rolling and well drained. 

GEOLOGY. 

Loose gray sands form the entire surface of Baker County. Beneath 
are red and yellow sands and sandy clays referred to the Lafayette ( ?) 
formation, and beneath the latter are rocks of Oligocene age. So 
far as is now known, no rocks of Miocene age are exposed in the 
county, and if any exist they are probably effectually concealed by 
the younger beds. The Oligocene rocks are covered by the younger 
formations, but their presence beneath the surface is readily inferred 
from the known stratigraphy. 



268 GEOLOGY AND GKOUND WATERS OF FLORIDA. 

The gray sand which covers the -surface of the county is in few 
places more than a few feet thick, and in many places on the upland 
is less than 5 feet. The sands and sandy clays of the Lafayette ( ?) 
formation have a maximum thickness of over 50 feet but do not 
average more than 25 to 30 feet. No direct information is available 
concerning the thickness of the Oligocene formations in Baker 
County, but from conditions in neighboring counties the thickness 
of the Vicksburgian limestones should amount to several hundred 
feet. 

WATER SUPPLY. 

Source. — Nearly all the wells in Baker County obtain their sup- 
plies from the red and yellow sand and sandy clays, though a 
few wells may draw from the surficial gray sand and some of the 
deeper wells may reach the older geologic formations. The amount 
of water supplied by the sands is sufficient for domestic and farm 
uses and in a few localities is large. The water level is near enough 
to the surface to make pumping easy, and in most wells suction 
pumps are used. 

Quality. — The shallow-well water is reported to be soft, but water 
from deeper wells would doubtless be hard and in some localities 
might contaiQ hydrogen sulphide. 

Development. — In Baker County the water now being used is taken 
from shallow wells which may be subject to pollution, especially 
when located near dwellings. The Vicksburgian limestones underlie 
the county, and would form a much better source of supply, though 
the water would undoubtedly be hard and might contain some 
sulphur, especially near the eastern boundary of the county. The 
depth to this limestone can not be stated with certainty, but wells 
drilled on the uplands should encounter it between 250 and 500 feet. 
Flowing wells can not be obtained, but the water should rise near 
enough to the surface to be raised with deep -well pumps. The 
quantity available would be practically unlimited. 

The town of Macclenny owns a driven well IJ inches in diameter 
and 23 feet deep, the water of which it uses for drinking. The ele- 
vation of the well is 125 feet above sea level and the head is several 
feet below the surface. The water, which is soft, comes from sands. 



BKADFORD COUNTY. 

General water resources of Baker County. 



269 





Topographic 
location. 












Shallow wells. 


Town. 


Source of water . 


formation. 


Depth. 


Supply. 


Quality 
of water. 


Macclenny 


Level 

do 

do 


Driven and dug 

wells. 
do 

Driven and drilled 
wells. 


Pleistocene 
sand. 

do 

do 


Feet. 
10-40 

8-i2' 


Ample 

...do 

...do 


Soft. 


Olustee 

Sanderson 


Do. 


Town. 


Principal water bed. 


Depth 

of 
deepest 
wells. 


Average 
thick- 
ness 

of sand. 


Depth 
to 

water. 


Remarks. 


Macclenny 


"Peninsular" lime- 
stone. 
.... do 


Feet. 
40 


Feet. 
10± 


Feet. 
Few. 


Supply constant; no sewerage 

system. 
No sewerage system. 


Olustee 


Sanderson 


do 


83 


Thin 




Do 

















BRADFORD COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Bradford County lies near the northern end of the peninsula and 
includes some of the highest land in that part of the State. Trail 
Ridge, which forms the divide between the Atlantic and the GuK 
drainage, is a long narrow upland extending nearly north and south 
near the eastern border of the county. Highland, Clay County, 
210 feet above sea level, is situated on this upland. The surface 
of the county is rolling and well drained, though it includes a few 
small ponds and lakes, especially on the upland. 

GEOLOGIC FORMATIONS. 

Distribution. — ^The surface of Bradford County is covered with a 
mantle of gray sand which forms a thin coating on red and yellow 
sands and sandy clays that are referred to the Lafayette ( ?) forma- 
tion. Rocks of Miocene age belonging to the Jacksonville formation 
are doubtless present, but as yet they have not been observed. The 
formations of the Apalachicola group probably underlie a large part 
of the surface of the county; beneath these are the Vicksburgian 
limestones. 

Thickness. — Owing to the absence of good well logs, the thickness 
of the various formations could not be satisfactorily determined. 
The gray sand probacy averages less than 5 feet, and the subjacent 



270 GEOLOGY AND GKOUND WATEKS OF FLORIDA. 

red and yellow sands and sandy clays in few places exceed 50 to 6^ 
feet. It is thought that the Apalachicola group may reach its maxi- 
nium thickness in Trail Ridge, but this could not be confirmee 
because it was impossible to obtain a record of the deep well a< 
Starke. There is no reason to doubt that the Vicksburgian lime- 
stones, as at St. Augustine, have a thickness of several hundred feet. 

WATER SUPPLY. 

Source. — The Lafayette ( ?) formation furnishes water for the shal- 
low wells in Bradford County. Many of the deeper wells appear to 
obtain water from the Jacksonville or from the formations of the 
Apalachicola group, but in many wells considerable doubt exists 
concerning the exact source of the supply. The deep well at Starke 
must penetrate some distance into the Vicksburgian limestones, and 
presumably it obtains its water supply from them. 

Quality. — In Bradford County the water from the Lafayette (?) 
formation is reported to be soft, but that from all the deep wells is 
hard. One well, near Providence, is reported to have encountered 
salt water and another to have procured water containing sulphur, 
but such waters appear to be rare, though they doubtless occur 
throughout the county at a depth of several hundred feet. 

Development. — Few of the shallow wells of Bradford County exceed 
30 feet in depth, and some of them are less than 10 feet. The depth 
to water varies with the nature of the materials and the topographic 
situation, but in few wells is it more than a few feet. Most of the 
deep wells are less than 150 feet, though one at Starke is 529 feet. 
Water in the deep wells stands some distance below the surface — 
in some nearly 100 feet, but in most from 50 to 70 feet below. This 
makes it necessary to use deep-well pumps and increases the cost of 
raising the water; but in spite of the added expense these wells are 
believed to be much more desirable than the shallow, because they 
are freer from danger of contamination by surface drainage. 

Springs are numerous in Bradford County, but few of them are 
large. The most important are the two Heilbron Springs, near Starke, 
and the Worthington Spring, near the town of the same name. The 
water from one of the Heilbron Springs was formerly bottled and 
sold for medicinal use. Worthington Spring is a health and pleasure 
resort. The water is used as a source of public supply and for a 
swimming pool; some of it is bottled for the market. 



BKADFOED COUNTY. 



271 



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272 



GEOLOGY AND GKOUND WATERS OF FLORIDA. 





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GEOLOGY AND GEOUND WATEKS OF FLORIDA. 273 

BREVARD COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Brevard County occupies a long narrow strip of the mainland on 
the east side of the peninsula, and includes a large island (Merritts) 
and some smaller islands and bars. Its surface is a flat plain less 
than 50 feet — over large areas less than 25 feet — above sea level. 
Swamps and shallow lakes are numerous, some of them being of con- 
siderable size. The most important inland body of water is Lake 
Washington, near the source of St. Johns River. Some smaller lakes 
west of Titusville are of interest because they contain brackish water, 
probably derived from springs and seeps, that have leached salt 
from sands and muds deposited on broad tidal floods or in lagoons 
formed when the land was slightly lower than it is at present. Many 
of the lakes are but a few inches deep and exist only during wet 
weather. 

The only important stream in Brevard County is St. Johns Eiver, 
which heads in the county and flows west of north, roughly parallel- 
ing the coast for a long distance before it turns eastward to the 
Atlantic. 

GEOLOGY. 

The surface deposits of Brevard County consist of light-gray 
Pleistocene sands. Beneath these sands are marls, limestones, or 
coquina, which in some places lie close to the surface and in others 
are buried beneath several feet of the sand. These subsurface mate- 
rials vary from place to place. West of Eau Gallic a soft shell marl 
consists of well-preserved remains of shellfish, similar to those now 
living on the adjacent coast, embedded in a matrix of nearly pure 
sand; and along the coast extensive exposures of coquina are com- 
posed of loosely cemented shells and shell fragments mixed with 
more or less sand. This coquina extends for some distance inland, 
in some places, as at Mims and near Titusville, forming ridges be- 
neath the sand. A hard compact limestone underlies Merritts Island, 
and extends beneath Indian River. 

Both limestone and coquina are regarded as Pleistocene, though 
they are older than the surface sands. Beneath them are sands and 
clays, which probably represent th© Pliocene and Miocene, but 
which, in the absence of satisfactory evidence, must be regarded as 
of doubtful age. At a depth of approximately 200 feet limestones 
and cherts, clearly of Vicksburg age, are encountered. 

The sections given below show the general character of the sub- 
surface formations at certain localities in Brevard County. The 
thickness of the Vicksburgian limestones is not known, but to judge 



274 



GEOLOGY AND GROUND WATERS OF FLORIDA. 



from well samples obtained farther north it may amount to several 
hundred feet. The aggregate thickness of all the younger forma- 
tions in few localities exceeds 200 feet. 

Log of Mrs. May Young's well, East Eau Gallie {sec. 21, T. 27 JS., R. 37 E.). 



Thickness. 



Depth. 



Sand, brown; contains many shell fragments 

Similar to the above, but with fewer shell fragments 

Sand; contains shell fragments and particles of dark material 

Clay, calcareous; fragments of limestone and chert and some sand 
Limestone, porous, light colored; contains fossils 



Feet. 





Feet. 


95 


95 


25 


120 


55 


175 


55 


230 


85 


315 



■ The fossils obtained between 230 and 315 feet are characteristic 
of the Ocala limestone and it is probable that the top of this lime- 
stone was encountered between 175 and 230 feet. 

Sellards has furnished the log of a well on the island opposite 
Melbourne. 

Log of well on island opposite Melbourne. 



Thickness. 



Depth. 



Sands, surface; bleached white on top, but showing considerable dark humus below 

Sand, yellow; the lower foot is the top of the driven- well water bed 

Coquina; supposed to be water bearing , 

Sand, fine, grayish 

Shell and sand ., 

Shell rock, hard 

Clay,greenish, or shale 

Flintrock, black; small shark teeth 

Clay, greenish, or shale , 

Flint rock, black; small shark teeth 

Clay, greenish, or shale 

Limestone, soft porous, no hard cap rock; strong flow of water 



Feet. 





Feet. 


3 


3 


8 


11 


10 


21 


30 


51 


5 


56 


63 


119 


54 


173 


* 


173i 


■i 


1741 


•i 


174f 


46 


2201- 


96 


316| 



From the soft Hmestone at 222 feet Sellards identified nummuhtes, 
which indicates that the rock belongs to the Ocala hmestone of the 
Vicksburg group. 

A well at Canaveral Lighthouse is reported to have penetrated the 
following materials : 

Log of well at Canaveral Lighthouse. 



Sand 

Shell bed 

Sand 

Quicksand 

Clay, blue 

Shell rock, hard 

Clay, blue 

Shell rock, hard 

Clay, blue 

Coquina, hard 

Clay, yellowish 

Shell rock; with water 




Depth. 



Feet. 

4 
24 
49 
64 

65 
75 
85 
125 
135 
185 
313 



BREVAKD COUNTY. 275 

It is difficult to decide from this log where the Vicksburgian lime- 
stones were encountered, but they probably include all of the last 
128 feet of the section. 

At Eau Gallic well logs indicate considerable variation in the 
character of the materials penetrated. A generalized log of wells of 
this locaUty was supplied by Capt. Alexander Near, who has drilled 
many deep wells. 

Generalized log of wells at Eau Gallie. 




Depth. 



Sand, white; contains a few layers of blue mud 

Shell rock; contains a little sand and is often greenish near base. 

Clay, bluish; with nodules of flint and some shark teeth 

Rock, hard, black; probably chert 

Rock, hard, white 

Shell rock: soft and hard, in alternate beds 

Limestone, soft 



Feet. 
65 
165 
230 
231 
232 
307 
492 



The bluish clay forming the third member of this log is of variable 
thickness and is sometimes entirely wanting. It probably repre- 
sents the Miocene or upper Ohgocene. The Vicksburgian limestones 
appear to have been encountered at about 230 feet. 



WATEB SUPPLY. 



Source. — In Brevard County there are two principal sources of 
water. Shallow wells obtain ample supplies from the Pleistocene 
sands, and deep weUs find water in the limestones of the Vicksburg 
group. These limestones yield a very large supply under head suf- 
ficient to give strong flows several feet above the surface. These 
facts are shown in the accompanying table of well records (p. 276) 
and though it is apparent that there is considerable variation in the 
yield and head of the different wells, yet for many the estimates are 
probably below the maximum. This is especially true of the height 
to which the water will rise, the head given being generally the 
height to which the water does rise and not the height to which it 
would rise if the casing were extended higher above the surface. 
The most reliable information indicates that the head at Eau GaUie 
is about 50 feet above sea level. Elsewhere in the county the water 
does not rise so high, though it flows several feet above the surface 
along the entire eastern border. 

The head of the water from the Pleistocene sands is not sufficient 
to furnish flows except on very low ground. The only flowing well 
from this deposit is in low ground in the village of Melbourne and its 
yield is comparatively small. 

The water level in the nonflowing wells is near the surface, and the 
water can be readily raised by small hand pumps. 



2Y6 GEOLOGY AND GROUND WATEES OF FLORmA. 

Quality. — The water from the Pleistocene sands is usually soft, but 
in some localities it may be rendered objectionable by the presence 
of organic matter. This is especially true in the vicinity of Titus- 
viUe, where shallow well water is reported to contain acid, which is 
presumably derived from the palmetto trees. Locally this water 
supply may also become contaminated by drainage from dwellings. 
The Vicksburgian limestones furnish hard sulphur water, which is 
satisfactory for general uses except where it contaias an excessive 
quantity of salt. In one area in the vicinity of Titusville all of the 
deep waters are more or less saUne. Probably the maximum saliaity 
is reached at Titusville, and the water becomes purer both north and 
south from that locality. At Sharpes, although it stni contaias 
considerable quantities of salt, it is fairly satisfactory for use ia 
irrigating orange groves and is used to a considerable extent for 
domestic supplies. The area yielding salt water is reported to extend 
northward nearly to Oak Hill, but in that direction the well records 
are few and the quality of the water is not well known. 

At Courtenay, on Merritts Island, the water is satisfactory for 
irrigation and can be used for domestic supply; at Canaveral Light- 
house a satisfactory supply of water is obtained from Vicksburgian ( ?) 
limestones. South of Sharpes some of the deeper weUs are said to 
contain saline water, though most of the flowing wells yield water 
satisfactory for all general uses. The cause for the salinity of the 
limestone waters in the vicinity of Titusville is not entirely clear, 
but it may be due to the leaching of salt from the Pleistocene sands 
near the western border of the county, or the beds may have been 
fiUed with salt water when this region was submerged during Pleis- 
tocene time. It is worthy of note that the head of the artesian water 
at Titusville is only a few feet above sea level, and this suggests that 
the artesian beds are not protected by a continuous layer of hard rock. 

Development. — Springs are not important sources of water in 
Brevard County, but both shallow and deep wells are extensively 
utilized. The shallow wells range in depth from 15 to 25 feet; a 
few do not exceed 10 feet, and the deeper ones are about 30 feet. 
The water obtained from these wells is ample for all ordinary purposes, 
but in some places are subject to pollution from impure surface waters 
sinking into the sand and descending to the permanent ground- 
water level. 

Along the east coast wells 150 to 250 feet deep may yield flowing 
water, but larger supplies must be obtained by deep drilling. Some of 
the wells are 300 to 500 feet deep, but supply water highly mineralized. 
Near Titusville satisfactory artesian supplies can not be obtained. 
Southward along the coast hard sulphur water is usually encountered 
at depths between 150 and 250 feet, and farther inland similar sup- 



r 



Principal trdls of Brevard County. 




CALHOUN COUNTY. 



277 



plies could doubtless be obtained. There are no public water sup- 
plies in Brevard County, and Titusville is the only town likely to 
need such a supply in the near future. Owing to the fact that the 
deep water at this locality is saline, it will be necessary to rely on 
shallow wells. A satisfactory supply from this source can probably 
be obtained a short distance from the town. 

General water resources of Brevard County. 





Topo- 
graphic 
loca- 
tion. 
















Shallow wells. 


Town, 


Source of water. 


Surface formation. 


Depth. 


Supply. 


Quality 
of water. 


Principal 
water beds. 


Cocoa 

Courtenay.. 
Eau Gallie.. 

Indianola... 

Melbourne.. 

Mims 

Titusville... 


Plain. 

...do... 
...do... 

...do... 

...do... 

...do... 
...do... 


Dn 
a 

'Dn 
\s 

Drj 
a 

Dn 

Dn 
Dn 


lied and dug tvells 
nd cisterns. 

.do 


Pleistocene sand . . 
do 


Feet. 
14-30 

12-24 
18-30 

12-30 

12-30 

15-20 
8-20 


Large. 

Ample 
...do... 

...do... 

...do... 

...do... 
...do... 


Soft 

...do 

Slightly 

hard. 

Soft 

Slightly 
hard. 

Soft 

...do 


"Peninsu- 
lar" lime- 
stone. 
Do. 


ven and drilled 

rells. 

lied and dug wells 

nd cisterns. 

ven and drilled 

rells. 

ven wells 

ven and drilled 
rells and cisterns. 


do 

do 

do 

do 

do 


Do. 

Do. 

Do. 

Do. 
Do. 




Deep wells. 


Aver- 
age 

thick- 
ness 
of 

sand. 


Depth 
water. 


Sewerage 

system. 




Town. 


Depth. 


Supply. 


Head 

above 

sea. 


Quality of 
water. 


Remarks. 


Cocoa 


Feet. 
170-350 

170± 
315-500 

210 
315-400 


Large. 
Good.. 


Feet. 


Sulphur; 

some salt. 

do 


Feet. 


Feet. 
10-15 

5-8 

25 

6-10 

12-25 

in-12 


None.... 

...do 

...do 

...do 

...do 


Supply constant. 


Eau Gallic.. 
Indianola . . . 
Melbourne.. 


Large. 
Good.. 
Large. 


50± 


do 

do 


65± 
'"36"" 

20+ 
10+ 


Do. 
One 40-foot well on low 


Mims 




ground has a weak 
flow. 


Titusville... 


282-780(?) 


Large. 


5-1- 


Salt and sul- 
phur. 




8-15 




.do 







CALHOUN COUNTY. 

By G. C. Matson. 



GENERAL FEATURES. 

Calhoun County comprises a long narrow area — in few places 
exceeding 25 miles in width — lying on the west side of Apalachicola 
Kiver and extendiag 30 to 40 miles northward from the Gulf of 
Mexico. The southern part of the county contains extensive swamps 
and, along Chipola River, some large bodies of stagnant water, the 
most noteworthy being Dead Lake. Toward the northern boundary 
the surface of the county becomes rolling and rises to an altitude of 



278 GEOLOGY AND GKOUND WATERS OF FLORIDA. 

over 150 feet, forming a more or less dissected upland, which extends 
northward into Jackson County. All the large streams are bordered 
by flat terraces, which merge seaward into broad plains sloping 
gently toward the coast. 

GEOLOGY. 

Below the 100-foot contour the surface deposits of Calhoun County 
are composed of gray Pleistocene sands. On the upland in the 
northern part of the county similar sands of residual origin are under- 
lain by red and yellow sands and sandy clay that are referred to 
the Lafayette (?) formation. In the latitude of Blountstown and 
Clarksville a belt of Choc tawha tehee marl at least 10 or 12 miles 
wide extends across the entire county. The Alum Bluff formation 
lies near the surface north of the exposures of the Choctawhatchee 
marl and dips thence gently southward. The sands of the Alum 
Bluff are well exposed in the vicinity of Carr and the underlying marl 
belonging to the same formation is exposed nearer Chipola River. 
The Chattahoochee formation underlies the entire county and rises 
near the surface in the extreme northern part. It outcrops along 
Chipola River north of the Alum Bluff exposures. The entire surface 
is underlain by the Vicksburgian limestones, but these rocks are 
deeply buried beneath the Chattahoochee and younger formations. 

On the uplands in the northern part of the county the gray sands 
are in few places more than 2 or 3 feet thick, but farther south gray 
sands of Pleistocene age may measure over 50 feet. The Choctaw- 
hatchee marl probably has an average thickness of less than 50 feet 
and the sands and marls of the Alum Bluff formation probably do not 
exceed 40 feet. The thickness of the Chattahoochee formation in 
Calhoun County is somewhat uncertain but may amount to as much 
as 200 feet; beneath it the Vicksburgian limestones extend down- 
ward to a depth of several hundred feet. 

WATER SUPPLY. 

Source. — All geologic formations in Calhoun County contain more 
or less water. On the uplands the gray sands are so thin that they 
are of little importance, but toward the south sands of Pleistocene age 
will supply an abundance of water. The Lafayette (?) formation 
yields large supplies of water throughout the upland portion of the 
county. The Choctawhatchee marl probably contains considerable 
water, but is penetrated by few weUs. The limestones of both the 
Chattahoochee formation and of the Vicksburg group are good 
aquifers. The supplies in the last named are probably exceptionally 
large; but, so far as known, no wells are deep enough to reach them. 

Quality. — The Pleistocene sands and the sands and clays of the 
Lafayette ( ?) formation contain soft water which is weU adapted to 



CALHOUN COUNTY. 



279 



all purposes except where its sanitary character is impaired by the 
percolation of impure surface drainage. All the older geologic 
formations should contain hard water, but as there are no wells 
procuring water from these rocks it is necessary to judge the charac- 
ter of the supplies by wells in adjoining counties. The Vicksburgian 
limestones will doubtless supply sulphur water; and, in the extreme 
southern part of the county, might yield saline water. 

Development. — Shallow wells obtain abundant water at depths 
ranging from 10 to 35 feet. The water is generally regarded as 
excellent, though locally, near dwellings or other sources of pollution, 
it may be contaminated. Where wells are properly cased and the 
water is obtained from beneath clay beds or other dense material 
there is little danger of contamination by impure surface water. 
Water obtained in sands that are not capped by impervious material 
may receive surface drainage, and imperfect casings are always a 
menace unless the wells are at considerable distances from any source 
of pollution. In the shallow wells, the water stands sufficiently near 
the surface to be readily raised by buckets or suction pumps. No 
deep wells are reported from Calhoun County, but it should be pos- 
sible to obtain good supplies of hard water within 100 or 200 feet of 
the surface throughout the upland portion of the county. Flowing 
wells could probably be obtained on the low ground near the coast at 
depths ranging from 300 to 400 feet. These wells should supply 
water similar to that from the flowing wells at Apalachicola. 

General water resources of Calhoun County. 



Town. 


Topo- 
graphic 
loca- 
tion. 












Shallow wells. 






Depth. 


Supply. 


Altha 


Plain . 

...do... 
...do... 


Due and driven wells. . 


Pleistocene and Lafa- 
yette (?) sands. 

Pleistocene sand 

do 


Feet. 
15-23 

18-30 
12-35 


Good. 


Blountstown 




...do 


Do. 


Clarksville 


...do 


Do. 














Shallow wells. 


Depth to 
water. 


Increase 
or de- 
crease of 
supply. 


Sewer- 


Town. 


Quality of 
water. 


Principal water bed. 


age sys- 
tem. 


Altha 


Soft 

...do... . 


Marianna limestone. . . 
do 


Feet. 

6 

18-28 

5-20 


Slight... 

...do 

do 
...do... 


None 


Blountstown 


Do. 


Clarksville 


Hard ._ . 


.do 


Do 















280 GEOLOGY AKD GROUND WATERS OF FLORIDA. 

CITRUS COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Citrus County extends from the Gulf coast eastward to Withla- 
coodhee River. Near the coast the land hes in a broad terrace which 
rises approximately 20 to 25 feet above sea level and represents an 
ancient sea bottom. It is bordered on the landward side by a more 
or less well defined scarp which separates it from the higher land to 
the east. Along Withlacoochee River is a broad terrace, which is 
several miles wide in the vicinity of Inverness, where it is occupied by 
Tsala Apopka Lake. In the vicinity of Dunnellon this terrace nar- 
rows appreciably but continues westward and merges with a terrace 
extending along the coast. In the vicinity of Dunnellon the terrace 
has an altitude of 40 to 60 feet. Some higher hills 70 to 100 feet 
above sea level are thought to represent remnants of a still higher 
terrace of marine origin. 

The interior of Citrus County is characterized by irregular rounded 
hills and depressions, representing sink holes; many of the latter 
are occupied by lakes. The sink-hole topography and large springs 
show the great extent of the underground drainage. 

GEOLOGY. 

The terraces of Citrus County are composed of gray Pleistocene 
sands which more or less effectually conceal the underlying materials. 
On the uplands there are several feet of gray or yellow sand repre- 
senting the insoluble materials remaining after the solution of the 
limestone and the weathering of the old siliceous formations. Some 
of this sand is yellow because of the presence of small amounts of 
hydrated iron oxide. 

Nearly all of Citrus County is underlain at moderate depths by the 
soft porous hmes tones of Vicksburg age, though in a few localities 
hard limestones intervene between the sands and the Vicksburgian 
hmestones. These hard limestones have been referred to the Haw- 
thorne formation and may be correlated with similar rocks that are 
widely distributed throughout the central section of the peninsula. 

The thickness of the gray Pleistocene sand is usually small, the 
average being probably not much in excess of 25 feet, though locally 
it may be somewhat greater, especially where there are sand dunes. 
The yellow residual sands are commonly less than 15 to 20 feet in^ 
thickness and in some places they are wanting. The Hawthori 
formation, where present, is represented by a few feet of hard lime- 
stone. The thickness of Vicksburgian limestones in Citrus County has 
not been determined, but it should amount to several hundred feet. 



CITKUS COUNTf. 281 

WATER SUPPLY. 

Source. — Citrus County has only two important sources of under- 
ground water. The gray and yellow sands yield an abundant supply 
for shallow wells, but the best water-bearing formations are the 
Vicksburgian limestones, which contain very large quantities of 
water and lie at moderate depths. 

Quality. — The surficial sands yield soft water. The Vicksburgian 
limestones supply moderately hard water, and deeper wells in the 
formations of this age may encounter sulphur or salt water. Water 
from the limestones is usually free from danger of pollution and is 
generally considered safer than that from the shallow wells. 

Development. — ^The water of the shallow wells is all derived from 
sui'ficial beds and, though generally satisfactory, it is not so safe for 
domestic supply as the water of the deeper wells. Abundant water is 
generally obtained at depths less than 150 feet in the limestones, and 
many wells drilled to them do not exceed 100 feet. In general the 
water, though hard, is free from sulphur and other objectionable 
mineral matter. Two miles north of Crystal River a well drilled to 
a depth of 1,900 feet yielded flowing water, but unfortunately its 
water contained much salt and other mineral matter that rendered 
it unfit for use. 

Citrus County has a large number of springs, some of which are of 
sufficient volume to give rise to good-sized streams ; such, for example, 
as Crystal River. The estimated flow of the principal spring is 
200,000 gallons per minute and the stream is large enough to be 
navigable for small steamers. A spring 7 miles south of Homosassa 
is the source of Chassahowitzka River. 



282 



GEOLOGY AKD GROUND WATERS OF FLORIDA. 






OP'S 



1^ 









. .2 a 

OH o 



f*1 



^ ^ 



^ CI , 



So 



1^ 



1 


Head of Crystal River; 

navigable. 
Head of Chassahowitzka 

River. 


si 








1 1 




8 
i 

O 

1 


a 






o "C 







a^ 
1^1 




o S 

Ph2 
o e 


i 

i 

1 




ill 


g-H 




0.2-1 




1. 

rt'g 


s 1 

If 

Q M 




1 


« 1 


1 













bepth 
to 
Nearest town o))rinci- 
post office, pal 
apply. 


Quality of water. 


Depth 

to 
second 
sup- 
plies. 


Remarks. 


Feet. 
Crystal River... 90 

Do 

Etna 97 

'''X^''^ li 

Felicia 300 


Hard 


Feet. 




Salt 






do 






Hard, sulphur — 
Hard 


40± 
40 




do 


Yields many gallons per minute. 


. do 


55± 

40 

35 


Do 

Do 


147 
90 


do 

do 




Tin 




do 


Protective clay. 


Hernando 

Do 


152 

122 

142 
98% 


do 


65± 

50± 
30 




do 




Do 


Hard, sulphur 

Hard 




Do 






100' 


do 


55 




Do 145 

Do 98 


do 




. ..do 




^ 


Do 121 


do 


60 




J)0 


do 




X)o 









Do!! !.. 130 

Do 70 


Hard 






. ..do 






Do 


do 







TnvTprnpQc; ! 66 


do 


40 

50 




Do 72 


do 




Do 127 


do 




Do 124 








Do 67 


Hard ... . 


40 




Lecanto 125 


do 




\)q 97 


.do 






Do ....... 









Maple 1 - 


Hard . . 















7685 



Typkal wells of Citrus County. 



N-»«„w„. 


Dtallon anl 




„.., 


■= 


\tc5°' 




~ 


Dtpt),. 


-r 


-- 


s 


„„a- 




Dept. 
prlncl. 
supply 

-'? 

122 


Qunlltyolwaler. 


si 

If 






Us.. 


AbovB 


sii?lS. 


„?. 


Remarks. 


|. 






ii 


ill 






13? 

■i 

1 

iS" 


[ 


I 

::::::■-:: 

IB 


vs' 


-20 


If 


::™: 


'iiorti?OTipiii.v;:: 
do 

do 

"■'"' 


S0± 


--™- 










































284 GEOLOGY AND GKOUND WATERS OF FLORIDA. 

group and the Jacksonville formation is about 300 to 350 feet and 
the thickness of the Vicksburgian limestones is several hundred feet. 

WATER SUPPLY. 

Source. — The water supplies of Clay County are obtained either 
from shallow wells in the sands or from deep wells penetrating the 
older geologic formations. The water in the shallow wells comes 
largely from the yellow and red sands underlying the surficial gray 
sands, though in a few places the gray sands may themselves yield 
water. The deep wells derive their water almost whoUy from the 
Vicksburgian limestones; the quantity available is usually large and 
the head is sufficient to furnish good flows in the vaUeys of the larger 
streams. A few shallow flowing wells, especially those located near 
Middleburg, appear to obtain water from some porous bed in the 
JacksonviUe formation, but in general this formation is not an 
important source of water. 

Quality. — The water from the shallow wells is commonly soft. 
The deep wells supply sulphur water containing considerable mineral 
matter. In a few localities this water is reported to be soft, though 
in comparison with the shallow-well water all the water from the 
deep wells is hard. When properly cased the deep wells are prac- 
tically free from danger of contamination by surface drainage except 
where impure water may be allowed to flow into wells that reach 
the source of supply. 

Development. — In the towns along St. Johns River deep wells are the 
principal source of supply, but in the remainder of the county most of 
the wells are shallow. The deep wells yield supphes that for all prac- 
tical purposes may be considered inexhaustible, though a large increase 
in the number of wells might cause a diminution in the head and yield 
if they were allowed to flow continuously. The table of well records 
indicates in a general way the depth at which supphes may be obtained, 
though it is seldom possible to make accurate forecasts because the 
depth to water-bearing beds varies within short distances. The head of 
the water in Clay County is sufficient to give good flows in the valleys 
of the streams, but it is doubtful if any important flowing weUs can be 
obtained where the ground is more than 50 feet above sea level. 
Apparently flowing wells may be obtained on higher ground in the 
northern than in the southern part of the county. Flowing wells 
can not be obtained on the highlands in the western part of Clay 
County, but good supplies of sulphur water may be had by drilling 
to the Vicksburgian limestones, which should be encountered at a 
slightly greater depth than in the St. Johns Valley. 

Springs are numerous in Clay County and some of them are impor- 
tant. Green Cove Spring, on the west bank of St. Johns River, gives 
an excellent flow of sulphur water, which emerges from a nearly 
circular orifice, several feet deep. The spring furnishes water to a 















Neares 


ok. 


Depth to 
principal 
supply. 


Character of water. 


Yield per 
minute. 


Remarks. 


Green C( 

Do. 
Do. 
Do.. 


eet. 


Feet. 


Sulphur. . 


Gallons. 








do 




100 feet sand; 250 feet clay. 















Near 

bottom. 

673 

500 

500+ 
362 


Sulphur 






Do., 

Do.^.:;; 


Hard, sulphur 

Sulphur 


150? 
90 

300 
Many. 


No lower supply. 
Protective cla^'s from 114 to 


Do., 




425+ feet. 


Magnoli 
Do. 




Soft, magnesia 

Sulphur 




Maxville 

Middleb 

Do. 















198 


Sulphur 


Few. 
300+ 


No lower supply. 
Do 


do... . 


Orange ] 

Do. 

Do. 
Do. 

Do. 
Do. 






do 








do 








...do 


Many. 
Many. 








do 
















Sulphur 


Many, 

Several. 
Many. 

Many. 
Many. 

Many. 

Many. 

16 




Do. 
Do. 

Do. 
Do. 

Do. 

Do. 
Russell. 
Walkill. 

Do. 

West To 
William 








Some lower supply. 






Sulphur 






Hard, sulphur 

Sulphur. . 














do 








...do... . 




e40 




















Many. 
Many. 








Hard, sulphur 





















well unknown. 



N«>r«Uo.™„rp.s. 


[ 


DrillCT. 


.r. 


-^s- 


loS" 


''w5°' 


„.. 


Doi.lh. 


^sr 


'■-'"i' H' 


s. 


X 


Sr 


— 


^ni^sr 


— 


GrwnavaSprlnes.... 

gs;;;;;;;:;;:;:;:;; 




1907 


:::::£:::::::: 


:::::t::::; 

3; 






voEo 

SI 

J50+ 
300+ 

2.50± 


7ncJ... 

r 


' „■;■.' 


+ 


TM. 


ft,,. 






Driiied:: 


DoSSiV.'!.'-. .:::::: 




"'i- 


do i 

suiphu,::;:::;:;::::::::;:;;:;:::- 
» -^-' ! r 


?,°o,ST™;;i;K''ir„,„ ■,., lo 






Xmwliiv'Misimvv 




"Jtof "" """ '""^^ 




"1 




r,2 


:■:■'?■:;;:;:::;: 










G.o.L.™pm»... 




;:::::£:::::::::::;:::' K: 












gS^.„.-.i„. 






'£SSa 


Hugh l-artridgc 


:;:::S::::: 

'viVtabuVe- 
'Y-miibuTis- 




:::::;:: ^l^ 


1 i 














M«n.v. 




Do 




»k°.'J:£r- 




■-^^^^ 


DiS^Jicg.*,, 




SomMowr supply. 








>M2 










Miiny. 


g; 




iiiij^^ 


^^■^.=i 


noraoslli- 


■|i6+ 













"'■".« 






:::::£::::::::::::::: 







1 WutGr-SuppI 
ft EatimQted. 



<■ Length ot easing: t 



CLAY COUNTY. 



285 



bathhouse and a large swimming pool appurtenant to a hotel. The 
water is thought to have medicinal value. 

Magnolia Springs, just north of Green Cove Springs, is a resort 
of considerable note. The water is obtained from artesian wells 
penetrating the Vicksburgian limestones. The flow is large and the 
quality excellent. In the western part of the county, about 6 miles 
from Starke, a spring, known as the Peck Mineral Spring, is also 
the center of a health and pleasure resort. 

General water resources of Clay County. 





Topo- 
graphic 
location. 






Surface 
mate- 
rial. 






Shallow wells. 


Town, 


Source of 
water. 


Surface 
formation. 


Depth. 


Supply. 


Qual- 
ity of 
water. 


Principal 
water beds. 


Highland 

Orange 

Park. 


Rolling . 
Plain.... 




Sand.. 




Feet. 








Drilled and 
driven wells. 


...do... 


Pleistocene.. 


28-35 


Moderatd . 


Good.. 


"Peninsular" 
limestone. 




Deep wells. 


Depth 

to 
rock. 


Depth 
to 

water. 


Sewer- 
system. 




Town. 


Depth. 


Sup- 
ply. 


Head 
(above 
sea). 


Quality, 
of water. 


Remarks. 


Highland 

Orange 
Park. 


Feet. 




Feet. 




Feet. 


Feet. 




Reported no deep well at 

Highland. 
Excellent water obtained 

at 30-35 feet; supply is 

constant. 


350-500 


Large. 


+60,65 


Sulphur and 
hard. 


30 


12± 


None.... 



Springs in Clay County. 



Name. 


Owner. 


Nearest town 
or post office. 


Direc- 
tion and 
distance. 


Dis- 
charge 

mmute. 


Topo- 
graphic 
surroimd- 
mgs. 


Us©. 


Emergence. 


Green Cove 


W.K.McKee. 
0. D. Setta... 
C.L. Peck.... 


Green Cove 
Springs. 

Magnolia 
Springs. 

Starke 




Gallons. 
500 

250+ 

20 


Plain 

...do 

In ravine.. 


Hotel, drink- 
ing; bot- 
tlrug. 
Drinking 
and bath- 
Drinking.... 


Boils from 


Springs. 

Magnolia 
Springs. 

Peck Mineral 
Springs. 




hole 60 feet 
deep. 
Flowing 
weU. 


6 miles 
east. 


Name. 


Source. 


Varia- 
tion of 
flow. 


Improvements. 


Quality 
of water. 


Tem- 
pera- 
ture. 


Trade naTne of 
water. 


Re- 
marks. 


Green Cove 
Springs. 

Magnolia 

Springs. 
Peck Mineral 


Vicksburg- 
ian lime- 
stone. 

...do 




None.. 

...do... 
...do... 


Hotel, bath- 
house, large 
swimming 
pool. 

Hotel 

do 


Sulphur... 

...do 

Clear and 


"F. 

78 

71 
71 


S 


ulpho - Magnesia 
Water. 

lagnolia Spring 


(a) 
(a) 




(a) 


Springs. 










colorless 









a Not muddy after rains; no contamination near. 



286 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

COIiTJMBIA COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Columbia County comprises a narrow strip in the northern part of 
the State, extending from the Georgia-Florida line southward for 
about 40 miles and having a maximum width of 18 to 20 miles. The 
northeastern part of the county is swampy, but farther south the 
surface is rolling and well drained; in the southern half sink holes 
indicate the presence of many underground streams of considerable 
size. The north-central part drains westward to Suwannee River 
and the southern part southward to Olustee Creek and Santa Fe 
E-iver. 

A narrow strip along Santa Fe River and some of its tributaries 
is less than 50 feet above sea level, but the greater part of the county 
rises to an altitude exceeding 100 feet. A broad tract in the central 
part is more than 150 feet above sea level, and uplands in the vicinity 
of Lake City are more than 200 feet above sea level. 

GEOLOGY. 

Below the 100-foot contour the surface deposits of Columbia 
County consist of gray sands of Pleistocene age, and on the uplands 
similar sands of residual origin are underlain by red and yellow 
sands and sandy clays referred to the Lafayette (?) formation. In 
the southern part of the county, where the Lafayette ( ?) formation 
is not present, the gray sands rest on yellow sands formed by the 
decomposition of the older formations. 

The Jacksonville formation has not been recognized in Columbia 
County, though it is possible that it is represented by some of the 
limestone on the upland near Lake City. The Apalachicola group is 
represented by clays, sands, and marls of the Alum Bluff formation 
and by limestones and sands of the Hawthorn formation. Both 
of these formations are exposed in the valley of Suwannee River at 
White Springs, and the limestones and cherts of the Hawthorn 
formation are exposed near Lake City, High Springs, Bass, Lake 
City Junction, and Fort White. The Vicksburgian limestones 
underlie the entire county and are near the surface from Bass to the 
southern boundary of the county. The Ocala limestone, the young- 
est formation of the Vicksburg group, is exposed in the phosphate 
mines near Fort White. 

Over most of the uplands the gray sands are from 3 to 5 feet thick, 
though locally they are somewhat thicker. The sands and sandy 
clays of the Lafayette ( ?) formation are in few places more than 50 
feet thick, and they probably average less than 30 feet. In the 
valley of Suwannee River the Alum Bluff formation is about 100 

















Nearest town or 
post office. 


Directio 
distar 


th 


Depth 

to 
prin- 
cipal 

sup- 
ply- 


Quality of water. 


Yield 
minute. 


Remarks. 


Bass 


Near 


t. 


Feet. 
65 
42 
55 
60 


Hard 


Gallons. 




Do 


do..-. 




do 






Brown .... 


do.... 




do 






Do 


do... 


... 


do 






Fort White 


do.... 


do 






Do 


1 mile nor 






. .do 






Do 


58 


60 


do 






Lake City 










Do 


2 miles we 


S2 


109 


Hard 


5 
Many. 


Second supply at 13 feet. 


Do 


Hard, sulphur.... 
do 


Second supply at 15 feet. 


Do 


i mile nor 
2 miles we 

10 miles sc 






Do 


80 
76 


118 
128 


Hard 






Do 


do .. 






Do 








LakeOgden 

Do 


1 mUe norinn 


60 
70 


Hard 


10 

Several. 

...do 






40 
40 


do 




Mikesville 








Winfield 




Hard 






Do 


f mile sou]. . . 
2 miles W€R9 


121 

88 


do 




Protective clay. 


Do 


... .do 


















76854°- 


-wsp Slo- 













Typical xveUs of Columbia County. 



Do:::;::: ' ": ■.' , ■ . ';:;';„', ^,';y, 

LQkeog'(ieii:::::::vr„,,]„" ,,,. <'■;■ : ■■ ■ 

mAv. '- ' • • 

'"|?::::;.;;:;:h-,:, , , ;,•, ^ . .,,,_.^ 



ter-Supply Pup,.r U. S. Gcol. 



COLUMBIA COUNTY. 287 

feet thick, but farther south it has been entirely removed by erosion. 
The exposures of the Hawthorn formation in few places amount to 
more than 20 or 25 feet, and the maximum thickness in Columbia 
County may be less than 50 feet. The underlying Vicksburgian 
limestones doubtless have a thickness of several hundred feet, but 
their exposures do not as a rule exceed a few feet. 

WATER SUPPLY. 

Source. — The water supply of the northern part of Columbia 
County probably comes from the sands of the Lafayette ( ?) formation 
or the underlying Alum Bluff formation. However, little definite 
information could be obtained, as there are few wells. Many of the 
wells- in the southern part of the county procure abundant supplies 
from the Vicksburgian limestones, and some of them probably obtain 
water from the Hawthorn formation. The deep well at Lake City 
penetrates the Vicksburgian limestones, from which it doubtless 
receives its principal supply. 

Quality. — The water from the shallow wells which penetrate the 
Lafayette (?) or the Alum Bluff formation is generally soft. The 
Vicksburgian limestones yield moderately hard water, with sulphur in 
some localities. , 

Development. — In Columbia County shallow wells are an important 
source of water, though the sanitary character of their supplies is some- 
times doubtful. Deep wells are most numerous in the southern part 
of the county, and the water, though hard, is considered better than 
that from the shallow wells, because there is little danger of pollution, 
except in a few localities where sewage is allowed to enter water- 
bearing beds. The practice of permitting impure surface water or 
sewage to enter the ground through sinks and wells should be pro- 
hibited, because it is apt to pollute the underground water and 
render it unfit for use. 

Flowing wells can not be obtained in Columbia County, but satis- 
factory supplies may be procured from the Vicksburgian limestones, 
at depths ranging from less than 100 feet in the southern part of the 
county to over 200 feet in the northern part. 

Lake City has the only public water supply in Columbia County. 
The system is owned by the town, and the water is obtained from a 
deep well, which penetrates the Vicksburgian limestones. The 
water is hard and contaias some sulphur but is said to be satisfactory. 

Springs are numerous in Columbia County, especially in the south- 
ern half of the county. Itchatucknee Spring, 6 miles southwest of 
Fort White, flows 180,000 gallons per minute and is the most impor- 
tant spring in the county. The water, which is hard and is colored 
amber by organic matter, comes from Oligocene limestones, 
doubtless of Vicksburg age. The water boils up from hammock 
land and flows a small stream. Its temperature is 74° F, 
76854°— wsp 319—13 19 



288 GEOLOGY AND GKOUND WATERS OF FLORIDA. 

General water resources of Columbia County. 





Topo 








Surface formation. 


Shallow wells. 


Town. 


graphic 
location. 


Source of water. 


Depth. 


Supply. 


Quality of 
water. 


Principal 
water beds. 


Columbia... 


Rolling. 
...do 


WeUs 




Feet. 








Fort White. 


do 


Clays or limestone . 








Limestone 


Lake City.. 
Watertown. 
Winfield .. 


Level. 

...do.. 

. do 




. .do .. . 


Clays . 


10-30 

"io^is' 


Gnnd 


Partly soft.. 

do 

do 


do 




Wells and lake. 
Wells .. 


do 

Some clay 


P 


.do... 
air 


do 

do 


















Deep wells. 


Aver- 
age 
thick- 
ness of 
sand. 


Depth 

to 
water. 




Town. 


Depth. 


Supply. 


Head 

above 

sea. 


Quality of water. 


Remarks. 


Columbia... 


Feet. 




Feet. 




Feet. 


Feet. 




FortWliite. 


""m 


Abvmdant. 




Hard 




50-60 
130-140 


No sewerage system. 

City sewerage system; 
typhoid not prevalent. 

No sewerage. 

Supply varies with sea- 
sons. No sewerage sys- 
tem. 


Lake City.. 
Watertown. 


...do 

...do 

do 


66-68 
66-68 


Hard, some sulphur 
Hard 






Winfield... 


do. 


4-10 



















DADE COUNTY. 

By Samuel Sanpord. 
GENERAL FEATURES. 

Except in the cities and villages along or near the line of the Florida 
East Coast Kail way, Dade County is sparsely inhabited, much the 
greater part of its area lying within the Everglades. Several short 
rivers and creeks, New, Middle, and Miami rivers. Snake and Arch 
creeks, and others, flow from the Everglades into Atlantic Ocean or 
Biscayne Bay, and at the south end of the county Taylor E-iver flows 
into the Bay of Florida. The relief is slight, reaching a maximum 
of possibly 30 feet and probably averaging less than 15 feet. 

GEOLOGY. 

Coquina is found along the ocean at many places from the north 
line of the county southward, the last reported outcrop south being on 
Virginia Key. Marls lie about the lagoons back of the beaches. 
Except for the low ridges of Miami oolite, sands cover most of the 
surface between the coastal swamps and the Everglades. The oolite 
lies in a strip about 10 miles wide at Fort Lauderdale and perhaps 20 
miles wide at Miami, extending from near Dania to Long Siding, and 
thence southwest to beyond Long Key. Peat, resting for the most 
part on sands, overlies the oolitic and nonoolitic limestones of the 
Everglades. 



DADE COUNTY. 289 

Nothing definite is known of the character, thickness, and struc- 
tural relations of the Pliocene and Miocene beds and no borings in 
the county have gone deep enough to reach the Oligocene beds. 

WATER SUPPLY. 

Source. — No very deep wells yielding potable water had been sunk 
in 1908 in the county, and all the water-bearing beds utilized are 
classed as Pleistocene. They include Miami oolite, surficial sands, 
coquuia, sandy marls with thin layers of limestones, and more or 
less compacted mixtures of quartz sand and shell fragments that do 
not outcrop. 

Springs. — ^Along the rock ridges of the Biscayne pineland are a 
number of springs, some of considerable size. The largest noted 
rises on the west side of the crest of the ridges just north of Miami 
and flows into a swamp from Miami River. It is supplied by rainfall 
on the sKghtly higher ground of the pineland. No special use is 
made of it. Other springs are found along the bay side, some of 
which may be supplied by water from the Everglades. On the 
property of Kirk Monroe, at Cocoanut Grove, are several springs, 
one or two of which emerge below tide level. A few of the bay side 
springs are used for domestic supplies and by fishermen. Once 
they were of more importance, because of the scarcity of fresh water 
for vessels plying along the coast of southern Florida. Their waters 
are clear but rather hard. 

There are said to be springs in the ocean bottom off Fort Lauder- 
dale and elsewhere, but the evidence needs confirmation. The writer 
doubts the existence of large offshore springs anywhere along the 
coast of the county. 

Wells. — The commonest weUs in Dade County consist of 1^ or 2 
inch pipe driven into the sand or worked down into the oolite. As 
water, except in the higher rock ridges or in dunes, in few places lies 
over 10 feet below surface, the cost of these weUs is small. Wells over 
50 feet deep are sunk by percussion or combined jet and percussion 
rigs; there are probably not more than 15 such wells in the county. 

The deepest well in the county, 387 feet, was sunk on the ocean 
beach 2 miles east of Fort Lauderdale and half a mile north of the 
House of Refuge. It found nothing but salt water. Vaughan 
obtained the following partial record from E. T. King, the driller: 





Partial log of well east of Fort Lauderdale. 








Thickness. 


Depth. 


Sand, etc 


• 


Feet. 

60 

1 

29 

290 


Feet. 
60 


Coquina 


61 


Sand, white 


90 


Coquina 


387 







290 



GEOLOGY AND GROUND WATERS OF FLORIDA. 



From the same driller Vaughan obtained the following record of a 
well at Fort Lauderdale: 



Log of well of P. N. Bryan, Fort Lauderdale, 






Thickness. 



Depth. 



Sand 

Oolitic limestone 

Sand 

Limestone 

Sand and gravel; fresh water 

Limestone, hard, white 

Sand and gravel 

Limestone, hard and soft, in alternating layers; salt water 



Feet. 



. 


Feet. 


2 


2 


12 


14 


16 


30 


* 


30J 


88 


m 


1 


69J 


31 


100§ 


8 


108J 



Most wells at Fort Lauderdale strike rock within 17 feet of the sur- 
face. The following record, also furnished by Mr. King, shows a notable 
depth to hard rock and a possible absence of oolite. The well is 
near the drainage canal, in what was swampy ground. 

Log of well 3 miles west of Fort Lauderdale. 




Depth. 



Muck 

Sand, white 

Sand, coarse, red. 
Gravel, coarse — 
Limestone; water 



Feet. 



The water, which is slightly hard but of good quality for domestic 
use, flows over the casing, which is about 2 feet above sea level. 

At Dania two wells are over 50 feet deep; others in the city and 
near by are much shallower, averaging less than 20 feet. The 
following record of the well used for the city supply was furnished to 
Vaughan by the driller, E. T. King: 

Log of city v;ell at Dania. 




Depth. 



Sands, surface 

Limestone, oolitic 

Mud, blue, some gravel 
Limestone, hard 



Feet. 



80 



A gasoline engine drives a pump that raises the water to an 
elevated tank 35 feet high, whence it is distributed to about 40 
families. The water is called soft. 

The wells between Dania and the vicinity of Miami call for little 
comment, the only one over 50 feet deep in 1908 being that of Dr. 



DADE COUNTY. 291 

J. N. McGonigle at Buena Vista, 3 mil^s north of Miami, which is 
about 55 feet deep. 

About 1 J miles north of Miami are four 6-inch wells that are used 
by the Miami Water Co. to supply the city. The water flows into an 
underground reservoir or large well, whence it is carried by pipe to 
the pumping station in the city and pumped to a large standpipe and 
distributing mains. In 1908 probably 2,000 people used this water for 
domestic supply. It is also used for boiler supply by several industrial 
plants, by steamboats, and the railway. Its quality is essentially 
the same as that of water from the well at Buena Vista. In fact, all 
shallow limestone waters in Dade County, away from the sea, probably 
differ little and resemble the Buena Vista and Miami well waters. 

The following generalized record of one of the wells shows the 
character of the materials penetrated: 

Generalized log of well of Miami Water Co., near Miami. 




Depth. 



Limestone, oolitic 

Cemented shell fragments with siliceous sand. 

Limestone, hard, yellowish 

Shell fragments and siliceous sand 

Sand, siliceous, fine and coarse 

Limestone, hard, light brownish 



Feet. 
15 

45 
47 

77 
87 



The driller's log of one of the shallower weUs was as follows: 
Log of well of Miami Water Co., near Miami. 



Thickness. 


Depth. 


Feet. 


Feet. 


3 


3 


7 


10 


3 


13 


7 


20 


7 


27 


20 


47 


10 


57 


4 


61 


2 


63 


8 


71 



Clay and marl 

Limestone, soft, gray 

Limestone, hard^ yellowish 

Limestone, medmra hard, gray 

Sand, yellowish 

Sandstone, hard, gray, siliceous 

Sand, white 

Limestone, hard, gray 

Sand, white, and pebbles 

Sand, fine, white, water-bearing stratum . 



In Miami many wells have been sunk for domestic supply or other 
purposes; they are mostly shallow — under 25 feet. A few wells — 
notably a large dug well at the ice factory — are reported to get salt 
under heavy pumping. The ice plant well is perhaps a quarter of a 
mile from the shore of Biscayne Bay, and the bottom of the well is 
about 10 feet below sea level. A field assay of the water is given 
on page 260. 

South of Miami numerous wells have been drilled or bored in the 
oolite. Depths to water vary with the elevation of the surface. 



292 



GEOLOGY AND GROUND WATERS OF FLORIDA. 



A few wells on rock ridges between Miami and Cocoanut Grove are 
35 feet deep; some near the shore get salty at. times. South of 
Cocoanut Grove, at Keys, Perrine, Naranja, and Homestead, wells 
are mostly 8 to 15 feet deep, the deepest, 35 feet, being at a quarry for 
railroad ballast at Keys. 

Artesian prospects. — The outlook for obtaining supplies of potable 
water near the coast in Dade County by wells deep enough to reach 
the Vicksburgian limestone, struck at over ^00 feet at Palm Beach, is 
distinctly unfavorable. Flows may be had, but the water is certain 
to be highly mineralized. The best prospects are for wells about 
100 feet deep and situated a little back from the shore, hke those at 
Fort Lauderdale, Dania, and Miami, but the water may not rise 
above the surface. In the northern part of the county, toward its 
western boundary, the chance of getting potable water from the Vicks- 
burg group is much better, but the surface waters are so good that 
deep drilling is unnecessary. There is practically no chance of finding 
good water by drilling on any of the keys east of Biscayne Bay. 



DADE COUNTY. 



293 



•a 





f 

a 






c 


f = 


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ft 


If 


•a^nuini lad ppjA 


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CI 

1 


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^ 
^ 


1 






IJ 1 


•sajiddns 


^ 


00 


2 ^ B 


•2I00J 0% ■q'\dQa 


^^ o o 2 g <= 


1 

1 


•aoBjjnsAopa 


^ 








,-1 CO 


•B8S8Aoqy 


^ 








<N (M 


•'B8S aAoqe uoi^BAaia; 


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•jai^auiBTo: 


^co 




(N C<l «D 


•q^^daa 


^K §8 1 1 5B 1 






L 

ft 


ft 

b 


6 







i 
ft 


^ 


II 


"a 

s 

'5 




V a 

II 

05 a 


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ii 


3 c 

CO T 




d c 

xi x: 


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73 -C 


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294 GEOLOGY AKD GBOUND WATEKS OE FLOEIDA. 

DE SOTO COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

De Soto County extends from Lake Okechobee and Caloosahatchee 
River northward for over 50 miles with a width of about 30 miles. 
Near the coast the low surface rises 20 to 25 feet above sea level, 
forming a broad terrace of Pleistocene age, which extends up Peace 
River but narrows appreciably toward the head waters of that 
stream. It also extends several miles northward from Caloosa- 
hatchee River, reaching the low lands bordering Lake Okechobee 
and Kissimmee River. In the vicinity of Lake Okechobee and Lake 
Istopoga the surface is low and flat and is covered by a luxuriant 
growth of saw grass and other aquatic plants. The central portion 
of the county is a high roUing upland, containing numerous depres- 
sions occupied by lakes. Lakes and swamps are also common in the 
southern half of the county. 

GEOLOGY. 

Below the 100-foot contour the surface deposits of De Soto County 
consist of gray Pleistocene sand except in the vicinity of the large 
lakes, such as Lake Okechobee, where there are areas of peat and 
muck. Beneath the Pleistocene sands of the western part of the 
county are beds of Pliocene age, which belong almost wholly to the 
Caloosahatchee marl, except near the northern end of the county, 
where there are small patches of land-pebble phosphate belonging to 
the Bone VaUey gravel. Beneath the Bone Valley gravel are lime- 
stone, sands, and clays of the Alum Bluff formation. Sands of the 
Alum Bluff probably reach the surface in the central portion of the 
county. The Tampa formation is not exposed, but it underHes the 
surface at no great depth. The Vicksburgian limestones extend 
beneath the entire county but are deeply buried under the younger 
formations. * 

It is difficult to give any correct estimate of the thickness of the 
various geologic formations in De Soto County, because few natural 
exposures exceed 10 feet and the well logs are difficult to interpret. 
In the western part of the county the Pleistocene gray sands are 
generally more than 20 feet thick, and farther east, especially in the 
vicinity of Lake Okechobee, their thickness probably exceeds 100 
feet. The Caloosahatchee marl is but a few feet thick where it is 
exposed in the vaUey of Peace River, but it doubtless thickens toward 
the east. The thickness of the Alum Bluff and the Tampa forma- 
tions can not be accurately determined, but it may exceed 300 feet 
in the western part of the county; no figures are available outside the 



















l- 


Depth 
to 

rock. 


Depth to 
principal 
supply. 


Quality of 
water. 


Yield per 
minute. 




N6a« 
po 


A.bove 

or 
below 
urface. 


Remarks. 




Feet. 

- 6 

- 6 

- 6 

- 6 


Feet. 


Feet. 
45 

45 
45 

45 


Sulphur very 

slight. 
do 


Gallons. 




D( 






D( 


do 






D( 


do 






D( 


Sulphur 






Bi 


- 1 

— 7 












Dfl 






1 




D( 

D< 
D< 

Bowli] 
D( 

Browi 


- 1* 

-n 




Near bot- 
tom. 
...do 


Sulphur 

do 

....:do 


100 

100 

Few. 

Few. 

Many. 




- 1± 

+10 




375 
210 


do 

Sulphur, slight 


80+ feet of protective clay. 


+ 9 
— S^ 


40 


140 


Sulphur 


20 


Second supply at 276 feet. 


CharlQ 

Fort Q-^'tn 


74 


173 


Hard, sulphur, 
do 


2i 




D 


+ 6+ 

+ 14 
+15 

J- R 






Sulphur 

do 

Hard, sulphur. 

Soft; iron, sul- 
phur. 


Few. 

Few. 
10 


Decreasing flow. 


D( 
D 

Glen. 




289 
300 

180 


Do. 


HicknU 
Hull. s 


Many. 








Sulphur 




Llverj 


■f- Sev- 
eral. 
+ 

+ 8 
+ 
+ 10 

+ 10± 




275 


do 


Few. 


Greatly decreased flow. 


Nocate 




150 




Dq 








Not completed. 


D( 






Sulphur 

do 


Many. 
Many. 




D( 








D( 


4 








Punta 




Sulphur and 

salt. 
do 


Many. 

25 
Manv. 
650 

Many. 
Many. 
Many. 
Many. 
Several. 
Many. 
Many. 




D(1|-2S 








D(H-28 






Sulphur 

do 




Ddi.40 








Dd-|-30+ 






do 




Dd^ 






do 




Doi- 






do 




Dct4-23+ 




427 


do 


Second supply at 185+ feet. 


Do- 1 


Soft 


Does not affect boilers. 


Dd4- 5 










Waucli- 2 






Sulphur 


Satisfactory in boilers. 


Do 
Da 

Dd 
Do 
Do 
Do 
Do 
Zolfo.. 










-32 
f 5 














450± 


Sulphur 


65 


























Not completed. 

Second supply at 60-150 feu i. 

No protective clays. 


f 6 




625 
350 


Sulphur 

do 


80 


Doll- n 


fin 










i 







c Estimated. 



■cadiu Electric LiRht, 



Typical mils of Ih Soto Couitti/. 



principal 
supply" 






Second supply ut 376 f»t. 



■::X^t. 






! -l-'-l -q"::::"!:. 



6 WiiMT-SuppIy I^per U. S. Oeol. i 



DE SOTO COUNTY. 295 

valley of Peace River. Here, as elsewhere in the peninsula, the 
Vicksburgian limestones should have a maximum thickness of several 
hundred feet. 

WATER SUPPLY. 

Source. — The surficial sands are an important source of under- 
ground water in the settled portions of De Soto County. The 
Caloosahatchee marl and Bone Valley gravel yield some water, but 
it is doubtful if these two formations are of more than local impor- 
tance. The best aquifers are the Vicksburgian limestones, which 
furnish large quantities of water to the deep wells used for the 
phosphate mines and for municipal supplies. 

Quality. — The surficial sands furnish soft water suitable for 
all purposes. Moderately hard water should be obtained from the 
Caloosahatchee marl and the Bone Valley gravel, but as yet no 
definite information concerning this is available. The Vicksburgian 
limestones yield hard sulphur water. 

Development. — Shallow wells obtain abundant water at depths 
ranging from 10 to 25 feet, though a few have been sunk 40 to 80 feet 
deep. The deeper supplies are probably more desirable than the 
shallow because they are presumably purer. The deep wells range 
from 100 to 300 feet in depth, and a few wells have been drilled to 
over 800 feet and some at the phosphate mines exceed 500 feet. The 
head of the water is sufiicient to raise it about 40 feet above sea 
level and hence flowing wells may be obtained on low ground. Good 
flows have been obtained in the valley of Peace River, at Arcadia, 
Bowling Green, Fort Ogden, Hickman, Hull, Liverpool, Nocatee, 
Wauchula, and Zolfo. Good flowing wells have also been drilled in the 
vicinity of Charlotte Harbor and flows are to be expected in 'a large 
area near Kissimmee and Caloosahatchee rivers. In the vicinity of 
Charlotte Harbor and in the valley of Peace River the water is hard 
and contains sulphur, but it is satisfactory for all general uses. Toward 
the south end of the county and in the valley of Kissimmee River 
the artesian waters probably contain more or less salt, but they may 
be fit for use. 



296 GEOLOGY AND GROUND WATERS OP FLORIDA. 

General water resources of De Soto County. 





Topo- 
graphic 
location. 


Source. 


Surface 
formation. 


Shallow wells. 


Town, 


Depth. 


Supply. 


Qual- 
ity of 
water. 


Principal 
water beds. 






Public supply; drilled and 
driven wells. 

Driven wells 

Driven and drilled wells... 
Driven and one drilled well 

Driven and two drilled 

wells. 
Driven and one drilled well 
Drilled and driven wells 

and cisterns. 
Drilled and driven wells... 

do 

Driven and two drilled 
wells. 


Pleisto- 
cene sand. 

...do 

....do...... 

...do 

...do 

...do 

...do 

...do 

...do 

...do 


Feet. 
15-50 

12-80 

10-20 

15-40 

5-25 

10-15 
10-40 

6-30 

12-40 
12-30 


Ample 

Large 

Moderate.. 

Ample 

...do 

...do 

...do 

-do 

Moderate.. 
Small 


Soft... 

...do... 
...do... 
...do... 
Good . 

...do... 

Soft... 

...do... 

Good. 
Poor.. 




Avon 

Park. 
Bowling 

Green. 
Ft. Meade 

Ft. Ogden 

Hull 

Nocatee. . 

Punta 

Gordo. 

Wauchula 

Zolfo 


Rolling . . 

Gently 
roUing. 

Nearly a 
plain. 

Plain 

...do 

...do 

...do 

...do 

...do 


lar" lime- 
stone. 
Do. 

Do. 

Do. 

■ Do. 

Do. 
Do. 

Do. 

Do. 
Do. 





Deep wells. 


Aver- 

thfck- 

ness 

of 

sand. 


Sewer- 
age 
sys- 
tem. 


Depth to 
water. 




Town. 


Depth. 


Supply. 


Head 

above 

sea. 


Quality of 
water. 


Remarks. 


Arcadia.. 
Avon 


Feet. 
150-380 


Large 


Feet. 
25± 


Hard 


Feet. 
50± 

20-40 

4-10 

6-10 
Sever- 
al. 
Sever- 
al. 
8± 
8+ 

60 


None . 

...do... 

...do... 

...do... 
...do... 

...do... 

...do... 
...do... 

...do— 
...do... 


Feet. 
8 

Variable. 

Several. 

Several. 
Several. 

Several. 

6 

4 

Several. 
Several. 


Flowing wells may be 
abandoned in Peace 
River valley. 


Park. 
Bowling 


140-280 

140 
280 

360 

500-600 
265-467 

350±? 
125-350 


Large 

...do 

Moderate . 

SmaU 

Large 

...do 

Moderate . 
...do 


-20 

Few. 
6 

4 

25+ 
25-30 

Few. 
3± 






Green. 
Ft. Meade 






Ft. Ogden 






Hull 






Nocatee. 
Punta 
Gordo 
"Wauchula 
Zolfo..... 


Hard 

Salt and 
sulphur. 
Sulphur. . . 
Good 





DTJVAL. COUNTY. 

By G. C. Matson. 
GENERAL FEATUHES. 

Duval County comprises a large area in northeast Florida extending 
from the coast westward to the highlands which form the axis of the 
peninsula. The surface of the county shows considerable variation, 
altitudes ranging from a few feet along the coast and in the valley 
of St. Johns River to nearly 200 feet above sea level in the southwest 
comer of the county. The transition from the lower to the higher 
levels is in part by broad, nearly level terraces. The lowest terrace 



DUVAL COUNTY. 297 

extends- inward several miles from the coast and occupies a large 
area bordering St. Johns River. Little of it lies more than 20 feet 
above sea level, but its inland margin is marked by an increase in 
altitude — in some places to over 40 feet. A second terrace borders 
the first and has an altitude of 40 to 60 feet above sea level. Between 
this terrace and the upland is a third terrace, with an altitude of 
70 to 100 feet above sea level. Near the southwest corner of the 
county the land is somewhat hilly, and the extreme corner of the 
county touches the high divide known as Trail Ridge. The county 
has few streams, but it contains broad areas that are flat and swampy. 
However, there are no lakes of any considerable size except those 
that form part of St. Johns River, and there does not appear to be 
a great amount of underground drainage through caverns such as 
characterize the lake region to the south and west. 

GEOLOGY. 

A large part of the surface deposits of Duval County consists of 
gray sands of Pleistocene age. These sands are underlain by red, 
yellow, and mottled sands and sandy clays which have been referred 
to the Lafayette (?) formation and regarded as Phocene, though in 
the absence of fossils their exact age can be inferred only from their 
relations to the underlying and overlying formations. A great 
thickness of Hmestones, shales, and sands, lying beneath the sands 
and clays of Pleistocene and Phocene age, belongs to the Jacksonville 
formation. The type locaHty of this formation is at Jacksonville, 
where it was encountered in digging a basin at the city waterworks. 
The log of the Jacksonville well (p. 124) shows the general character of 
the formation and indicates that it may have a thickness of at least 
461 feet. The Hawthorn formation may be represented by beds 
of clay and limestone, but there is some doubt as to its presence in the 
Jacksonville well; toward the south and west it is extensively 
developed and it not improbably extends into Duval County. The 
entire county is underlain by the Vicksburgian limestones, but they 
are so deeply buried that their presence can be detected only in 
artesian- well drillings. 

The Pleistocene gray sand is comparatively thin, probably in few 
places exceeding 30 feet and averaging not more than 20 feet. The 
underlying red, yellow, and variegated sands of Pliocene age may 
in some localities be 30 or 40 feet thick. At Jacksonville their 
thickness appears to be about 20 feet. The thicknesg of the Jackson- 
ville formation may be nearly 500 feet, though from the conditions 
at St. Augustine it is inferred that it thins toward the south. The 
Hawthorn formation is apparently thin. The Vicksburgian hme- 
stones have been penetrated in wells for several hundred feet without 



298 



GEOLOGY AND GEOUND WATEKS OF FLORIDA. 



reaching the underlying formation. The following well logs show 
the thickness of the formations at different places: 

Log of the 8-inch artesian ivell^ of the Seaboard Air Line Railway shops, at Jacksonville. 



Thickness. 


Depth. 


Feet. 


Feet. 


26 


26 


10 


36 


39 


75 


15 


90 


20 


110 


60 


170 


40 


210 


1 


211 


11 


222 


11 


233 


3 


236 


4 


240 


5 


245 


8 


253 


15 


268 


72 


340 


5 


345 


3 


348 


5 


353 


27 


380 


3 


383 


9 


392 


36 


428 


4 


432 


3 


435 


2 


437 


47 


484 


4 


488 


2 


490 


4 


494 


3 


497 


21 


518 


6 


524 


179 


703 



Sand, with a few feet of clay near the surface 

Clay 

Clay, soft, with thin layers of rock, varying from 2 to 12 inches thick 

Limerock, solid 

Clay, same as 36 to 75 feet 

Clay, stiff 

Clay, sandy, soft 

Shell rock 

Clay, sandy 

Clay, stiff 

Clay, soft 

Clay, tough, sticky 

Clay, sandy 

Clay, stiff 

Sandstone 

Clay 

Clay and rock; in layers 

Clay 

Sand, coarse, gray; flow 12 gallons per minute 

stone and clay; in layers 

Rock, hard 

Clay, hard 

Clay 

Clay, soft, sandy 

Clay, tough 

Sandstone, blue 

Pipe clay, hard 

Sand, coarse 

Shell rock 

Clay 

Limerock, white, soft 

Porous rock; flow 1,000 gallons per minute 

Rock, white, hard 

Rock, porous; flow 1,000 to 1,500 gallons per minute 



a Casing, 8-inch, to 499 feet. 
Log of well of Florida East Coast Railway at May port. 





Thickness. 


Depth. 




Thickness. 


Depth. 


Sand and mud 


Feet. 
58 

3 
23 

3 
73 

5 
35 
40 
35 

5 
70 


Feet. 

58 

61 

84 

87 

160 

165 

200 

240 

275 

280 

350 


Rock 

Clay 


Feet. 
3 

\? 

9 

5 
20 
40 

7 
180 

3 


Feet. 
353 


Rock. 


363 


Sand 


Rock 


366 


Rock. . . 


Clay 


375 


Clay 


Rock 


380 


Rock 


Sand 


400 


Clay 


Clay . 


440 


Sand 


Soft rock 


447 


Clay; fresh water at 250 feet . . . 
Rock 


Rock, soft; water bearing 

Rock 


627 
630 


Sand 











DUVAL COUNTY. 

Log of well of Florida East Coast Railway at Bumside. 



299 



Sand 

Clay 

Soapstone 

Clay 

Rock, soft 

Clay 

Rock, soft 

Sand and clay 

Sand 

Clay 

Rock 

Clay 

Rock 

Clay 

Sand 

Rock 

Clay 

Sand and clay 

Clay 

Sand 

Clay 

Rock 

Clay 

Rock 



Thickness. 


Depth. 


Feet. 


Feet. 


35 


35 


12 


47 


43 


90 


50 


140 


15 


155 


5 


160 


10 


170 


15 


185 


25 


210 


65 


275 


5 


280 


10 


290 


2 


292 


12 


304 


5 


310 


I 


311 


9 


320 


20 


340 


10 


350 


7 


357 


4 


361 


2 


303 


6 


369 


1 


370 



Depth. 



Clay 

Rock 

Sand 

Rock 

Clay 

Rock 

Clay 

Rock 

Water 

Rock 

Water 

Rock, soft . 
Rock, hard 

Water 

Rock 

Unknown . 

Rock 

Unknown . 

Rock 

Unknown. 

Rock 

Rock, soft . 
Rock, hard 




Partial log of well of city of Jacksonville. 

Depth in feet- 
Marl, soft, white ; contains fossils 375-385 

Marl, soft, bluish, sandy 443-460 

Limestone, silicified 460-470 

Limestone, gray ; contains fossils 470-471 

Limestone, silicified 487-492 

Limestone, silicified ; resembles quartzite , 504-506 

Limestone, soft, white; contains fossils 524-750 

The soft white Hmestone encountered beneath the last siHcified 
layer yields a strong flow of sulphur water. The log of this well is 
incomplete, though the conditions are doubtless similar to that 
shown by the log given on page 124. The soft white limestone at the 
bottom of the well contains fossils indicating Vicksburg age. The 
material from 375 to 506 feet probably represents the Jacksonville 
formation, though the lower part may belong to the Hawthorn 
formation. 

WATER SUPPLY. 

Source. — The Pleistocene and Pliocene sands furnish an abundant 
supply of water for shallow wells. The water table usually stands 
within a few feet of the surface and suction pumps may be used 
advantageously. Because of the small cost and the ease with which 
the water may be raised, shallow wells are extensively used for 
domestic and farm supphes. The sand beds in the Jacksonville 
formation are water bearing, but the supplies are seldom utilized; 
the head is sufficient to bring the water near the surface in the vicinity 
of Baldwin and to give flowing wells on low ground some miles 
southeast of that town. 



300 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

The best water supplies of the county are obtained from the 
Vicksburgian limestones, the water in which is under sufficient 
pressure to yield strong flows near the coast and in the St. Johns 
River valley. 

Quality. — Pleistocene and Pliocene sands yield soft water. Little 
is known concerning the quality of the water yielded by the Jackson- 
ville formation; in the well at Yellow Water Schoolhouse it yielded 
soft water, but it appears probable that it also yields hard water 
from certain of its limestone beds. The Vicksburgian limestones 
furnish hard water containing hydrogen sulphide, and some of the 
very deep wells have found saline water in these formations. 

Development. — Shallow wells ranging in depth from 5 to 60 feet 
are used in several parts of Duval County but most commonly 
15 to 25 feet deep. The deeper wells are usually sunk in order to 
obtain more or better water. Shallow wells are regarded as satis- 
factory if they are located some distance from buildings or if the 
aquifers are capped by impervious clay that excludes impure surface 
drainage. In the vicinity of Baldwin much water is obtained from 
the Jacksonville formation at 80 to 100 feet. 

Flows may be expected from the Jacksonville only on low ground 
and they appear to be largely confined to the western part of the 
county. The well of H. J. Reid at Mandarin obtains water from 
this formation at 157 feet, but the water does not have sufficient head 
to rise to the surface. 

A large number of wells have been drilled to the Vicksburgian lime- 
stones and obtain large supplies. In the vicinity of Jacksonville 
the water has a head of about 65 feet above sea level, sulficient to 
give flows strong enough to be used for water power. The water 
contains a large quantity of inorganic material, including sulphur, 
but is usually regarded as satisfactory. Flowing wells from this 
formation are most numerous in the vicinity of Jacksonville and in the 
villages along the coast; they range in depth from slightly less than 
500 feet to more than 1,000 feet. 

Jacksonville, South Jacksonville, Riverside, and Pablo Beach 
all have public water supplies obtained from wells penetrating the 
Vicksburgian limestones. The water is regarded as satisfactory 
for all purposes and the quantity is practically unlimited. At Jack- 
sonville the water is permitted to flow into a reservoir from which 
it is pumped into distributing mains. At Pablo Beach and South 
Jacksonville the water flows directly from the wells into the mains, 
and the systems depend on the artesian head for pressure. Practically 
no information could be obtained concerning the public supply of 
Riverside. 

No large springs are reported from Duval County, but small springs 
are not uncommon. 



i 



62 



+50 



-16 
47 



+60± 
+ 
+Many. 



48 
+15 

+ 

62 

50 

+35 

30 ± 
+40 

+ 

-2 

+Many. 

+47 

+55 

+30+ 
+Few 

+20 

+0 
+30 

+ Several 
+40+ 
+30 
+46 

+40+ 




dOp 



Typical ivells oj Duval County. 




Vicksburgiim liniBstone?. 



City supply.... 
Public supply.. 




ESCAMBIA COUNTY. 

General water resources of Duval County. 



301 





Topographic 
location. 


Source. 


Surface 
formation. 


Shallow wells. 


Town. 


Depth. 


Supply. 


Qual- 
ity of 

water. 


Principal 
water bed. 




Plain 


Driven, dug, and 
drilled wells. 

Artesian well and 
driven well. 

Public supply 
from artesian 
wells; shallow 
wells. 

Driven and dug 
wells; one ar- 
tesian well. 

Public supply 
and surface 
wells. 

Shallow and ar- 
tesian wells. 

Public supply 
from artesian 
well; shallow 
wells. 


Pleisto- 

c e n e 

sands. 

...do 

...do 

...do 

...do 

...do 

...do 


Feet. 
1&-28 

12-23 
40-60 

&-10 

10-25 

10-20 
30-60 


Ample 




"Peninsu- 


Bayard 


do 


Moderate . 
Large 

A b u n - 
dant. 

Moderate . 

Ample 

Large 


Good. 
Soft.- 

Soft.. 

...do.. 
...do.. 


lar" lime- 
stone. 


Jacksonville... 

Mayport 

Pablo Beach... 
St Nicholas 


Plain 20 feet 
above sea 
level. 

Low sand 
dunes. 

Sand dunes 
and beach. 

Plain.. 


"Peninsu- 
lar" lime- 
stone. 

Do. 
Do. 
Do. 


South Jack- 
sonville. 


Plain 20 feet 
above sea 
level. 


Do. 





Deep wells. 


o 


2 
2 


1 
s 


In- 
crease 
or de- 
crease 

of 

sup- 
ply. 


Sewerage 
system. 




Town. 


Depth. 


Supply. 


Head 

above 

sea. 


Quality 
of water. 


Remarks. 


Baldwin 


Feet. 
92 

500±(?) 

400-1,020 




Feet. 


Sulphur. 


Ft. 


Ft. 


Feet. 
to sev- 
eral. 


None 
...do.. 


None 




Bayard 


Large. 
...do... 


-1-60-65 

50± 

35 -f 
30-f- 


Hard 
sulphur. 
Sulphur. 








Jacksonville., 
Mayport 


35-40 

■56+ 
50± 

25 ± 


35 ± 

lOi 
50± 

25 ± 


5± 


...do.. 

...do.. 
...do.. 
...do.. 


Discharges 
into river. 

None 

do 

do 

do 




Pablo Beach . 








St. Nicholas.. 


55-65 
400-800 


Large . 




Deep wells 

best. 
No typhoid 

fever. 


South Jack- 
sonville. 


...do... 


50± 


Sulphur. 



ESCAMBIA COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Escambia County, which lies in the extreme western part of Florida, 
comprises a narrow area extending from the Gulf of Mexico north- 
ward to the Alabama line. Its western boundary is formed by 
Perdido Kiver and its eastern boundary by Escambia River. The 
southern part of the county is more or less deeply indented by bays 
and includes a narrow island, some 40 miles long, which incloses a 
body of water known as Santa Rosa Sound. Altitudes in the county 



302 GEOLOGY AND GROUND WATERS OF FLORIDA. 

range from a few feet above sea level near the Gulf to more than 250 
feet near the northern boundary. In the southern part of the county 
is a broad flat terrace which extends several miles in from the coast and 
merges into narrow terraces that extend inland along the principal 
streams. Near the coast the altitude of the terrace probably does not 
exceed 25 feet, but it apparently increases slightly toward the north. 
A similar terrace at a somewhat higher level extends across the 
southern part of the county and along each of the principal streams. 
Much of the surface consists of high rolling uplands, which are dis- 
sected in the vicinity of the large streams but which elsewhere form 
extensive plains. The uplands form part of the broad plain that 
extends northward from the northern end of the State into Alabama 
and Georgia. Lakes and swamps are comparatively rare except near 
the coast, where the surface is so flat that bodies of shallow wat^r 
accumulate during the rainy season. 

GEOLOGY. 

The lowland of Escambia County is mantled by gray Pleistocene 
sands, thin near the uplands and thick near the coast. In the uplands 
a few feet of gray sand rests on red and yellow sands, sandy clays, and 
sandstones referred to the Lafayette ( ?) formation. These deposits 
are extensively developed in the northern part of the county and 
extend several miles beyond Muscogee. Little is known concerning 
the geologic formations underlying the surficial sands and sandy 
clays. Recent well drilling in the valley of Escambia River has 
shown the presence of considerable deposits of gray micaceous sand 
and marl 100 to 200 feet below the surface. Samples obtained in 
drilling wells at Cantonment and Pensacola indicate that sands 
and marls of Pleistocene, Pliocene, and Miocene age are well developed, 
especially in the southern half of the county. The well at Canton- 
ment also encountered a light-gray to white limestone, and from knowl- 
edge of the geologic succession farther eastward it is inferred to be- 
long to the Chattahoochee formation. The Vicksburgian limestones 
are doubtless present, but they are so deeply buried beneath the 
younger rocks that they have probably not been reached by any of 
the wells. 

Concerning the thickness of most of the geologic formations under- 
lying Escambia County no reliable information is available. On 
the uplands the average thickness of the residual gray sands is 
probably less than 5 feet; farther south sands of Pleistocene age 
attain a maximum thickness of over 100 feet and pass downward 
into interbedded sands, marls, clays, and gravels at least 900 feet 
thick. 



ESCAMBIA COUNTY. 



303 



The following section shows the thickness of the formations at the 

places named: 

Log of well at Cantonment. 



Thickness. 



Clay 

Sands, coarse, and fine gravel 

Clays,, variegated 

Sands, coarse, and fine gravel 

Clay, yellowish 

Gravel, fine 

Clay, yellow 

Gravel 

Clay 

Gravel 

Clay 

Sand, fine, gray, with small gravel at bottom 

Clay 

Saiid, yellowish; gravel at bottom 

Clay, greenish ; shells at bottom 

Sand, fine, green 

Clay, gray, with shells 

Sand, fine, gray 

Clay, green 

Sand, fine 

Clay, gray, with large shells 

Gravel, coarse 

Rock 

Clay, green 

Sana, fine 

Rock 

Clay 

Rock 

Clay 

Rock 

Clay 

Rock 

Clay 

Rock 

Sand , gray 

Rock phosphate 

Clay, shaly 

Rock phosphate 

Rock 

Clay 

Rock 

Clay 

Rock 

Clay 

Rock 

Clay 

Rock 

Clay 



Feet. 



67 

3 

80 
10 
40 
10 
20 
10 
30 
15 
15 
60 
10 
50 
200 
60 
50 
10 
150 
10 
90 
10 

li 
59f 
15 

1 
20 
10 
15 
10 
60 

3 
45 

5 
30 
20 
45 
12 

5 
25 

3 
15 

3 
15 

5 

5 

2 

5 



Log of the well of Lee & Co., 41 miles south of Pensacola. 



Soil, black 

Sand, gray 

Sand, white 

Clay, dark, sandy 

Sand, white, with bits of wood 

Sand, gray 

Sand, coarse, white 

Sand, coarse, yellowish 

Gravel, fine 

Gravel, coarse 

Sand, fine, white 

Sand, gray, slightly micaceous 

Sand, brownish yellow, and white gravel 

Sand, coarse, gray; shell fragments 

Clay, dark, sandy 

Sand and gravel 

Clay or shale, dark, sandy 

Sajid, coarse, with gravel 

Clay or shale, dark, sandy 

Sand, coarse, gray 




76854°— wsp 319—13 ^20 



304 



GEOLOGY AND GEOUND WATERS OF FLOEIDA. 



WATER SUPPLY. 

Source. — Probably all the geologic formations underlying Escam- 
bia County are water-bearing, but it is frequently impossible to 
d-etermine the exact bed from which wells obtain water. On the 
upland most of the shallow wells doubtless procure water from the 
Lafayette ( ?) formation and on the lowland from the Pleistocene sands. 
The deeper wells penetrate the older formations. 

Sands and marls in the Escambia Valley furnish large supplies of 
water which head several feet above the surface. 

Quality. — In most places the Pleistocene sands and the Lafayette ( %) 
formation furnish soft water, but locally the water from the Lafa- 
yette ( ?) is said to be slightly hard. All of the older geologic forma- 
tions supply hard water, though in some wells the amount of inorganic 
material is so small as to be unimportant. A few of the drilled wells 
yield sulphur water and some of the very deep ones salt water. 

Development. — Most shallow wells obtain large supplies of water 
at depths ranging from 15 to 50 feet, though some of them have been 
sunk 65 to 100 feet. The water from the shallow wells is used for all 
purposes and is regarded as satisfactory, though supplies obtained 
near dwellings or other sources of pollution may be unsafe for domes- 
tic use. Drilled wells range in depth from less than 100 feet to more 
than 1,600 feet, but the deeper ones yield water too saline to be used. 
Excellent flowing wells have been obtained at Pine Barren at about 
150 feet and at 181 feet at Mulat. These are among the best flowing 
wells in western Florida. The public water supply at Pensacola is 
taken from wells 112 to 150 feet deep. The water is said to be soft 
and the quantity is ample for the needs of the city. 

General water resources of Escambia County. 

















Shallow wells. 


Town. 


location. 


Source of water. 


mation. 


Depth. 


Supply. 


Quality of 
water. 


Principal 
water beds. 


Bluffsprings 


Plain 


Wells and 

springs. 
Dug and drilled 

wells. 
WeUs 


Sand 


Feet. 
15-40 

28-43 

50-65 


Large. . 
...do.... 
Ample. 


Soft; some 

hard. 
Hard 

Soft 


Marianna 


Century 

Goulding... 
MiUview.... 


do 

Gently rolling. 


Pleis 1 c e n e 

sand. 
do 


limestone. 
Do. 

Do. 
Do. 


Molino 


Plain 


Wells 


Sand 


25-32 


Ample. 


Soft 


Do. 














Deep wells. 


Aver- 

thfck- 
ness of 
sand. 


Depth to 
water. 


Increase 

or de- 
crease of 
supply. 


Sewerage 
system. 




Town. 


Depth. 


Supply. 


Qual- 
ity of 
water. 


Remarks. 


Bluflfsprings 
Century 


Feet. 
40 

85 






Feet. 
2-12 


Slight... 

None. . . . 
...do 


None.... 

...do 

...do 

...do 


Feet. 
20 

12-18 
50-1- 


Some large springs about 1 


Good.. 


Hard 


mile from railroad sta- 
tion. 


Goulding... 
Millview... 








Molino 


32 








Slight... 


...do 


10 


Some surface water used 




















by a mill. 





eand 
face. 


Depth 

to 
prin- 
cipal 

supply. 


Quality of water. 


Depth 
to 

second 
sup- 
ply. 


Yield 
minute. 


Remarks. 


t. 
—106 


Feet. 


Hard 


Feet. 


Gallons. 




—40 


do 








-96 




do 








-20+ 


82 


Soft 


16 






—47 


do 


Many. 
125 
120 
150 




+38 


'"'ieo' 


Sulphxir.. 




Forms little scale. 


+38 




160 




+60 






—2 


155 

} 198 
385 


Sulphur.. . 






—8 


Soft 








3, +8 



(Soft at 70, good at 198, 
\ salt at 1,320. 

Sulphur 


70 
1,030 

260 


} Many. 
Good. 


Small flow. 


—24 


do 




—24 




Hard 








-16 






55 
Many. 
Many. 







195 
125 


Soft. 


125 


Three wells 


-3 


Fair 


Do 




Sulphur 






-24 




. do 












Salt 












































+ 1 


52 


Slightly hard... 




Several. 


Flow increases at high tide; water 
forms some scale in boilers. 








+30 




Saltv 








-8 








Two wells. 




70 

53 

112-135 
75 








Attempt to get flow, but no increase in 

head below 70 feet. 
Three wells. 


+4 






6 


-S-12 


Soft 




Thirteen wells. Water forms no scale. 


+ 1 








Head varies from J to 3 feet above sea 


—24 








level. 















iter of good quality that requires filtering in order to remove a small amount of iron. 



Typical wells of Escambia County. 



f+d from 



GEOLOGY AND GROUND WATERS OF FLORIDA. 305 

FRANKLIN COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Franklin County is on the Gulf coast at the mouth of Apalachicola 
River. The surface is low and flat and includes extensive areas of 
swamp land. A large part of the county is only a few feet above 
sea level and its greatest altitude is probably not over 25 feet. The 
coast is bordered by two long narrow islands — St. George Island and 
Dog Island — which inclose St. George Sound and Apalachicola Bay. 

GEOLOGY. 

In Franklin County the older geologic formations are concealed by 
sands of Pleistocene age. At the surface these sands are light gray, 
but they give place below to darker sands, which may be Pliocene 
but are at present of undetermined age. Beneath them are the ''Sop- 
choppy limestone" and the limestones of the Chattahoochee forma- 
tion, which in turn are underlain by limestones of Vicksburgian age. 

As satisfactory well logs are lacking the thickness of the various 
formations can not be determined. The weU of the CarrabeUe Oil & 
Development Co., at CarrabeUe, passed through about 70 feet of 
sand and then entered the ' 'Sopchoppy limestone." The ' 'Sopchoppy' 
and Chattahoochee appear to have continued to a depth of at least 
240 feet. Some of the deep weUs at Apalachicola pro'bably pene- 
trate the Vicksburgian limestones, but in the absence of samples it is 
impossible to teU at what depth these rocks were reached. The 
following sections show the thickness at the points given: 

Partial log of the well of the CarrabeUe Oil & Development Co. 

[From samples in possession of the U. S. Geological Survey.] 

Feet. 

Sand, light brown 18-20 

Sand, dark brown 49- 50 

Sand, dark brown 58^ 60 

Sand, light yellow, coarse; and fine gravel with some shell frag- 
ments 65- 67 

Sand, dark brown 68- 69 

Same ; with shell fragments 69- 70 

Limestone, hard, gray 70- 72 

Same; with casts of shells 78- 84 

Clay, greenish ; containing limestones 100-110 

Limestone, dark gray, granular 120-125 

Limestone, dark gray 139-141 

Limestone, light gray 140-144 

Limestone, porous, gray 146-149 

Limestone, light gi-ay , 159-160 

Clay, dark gray; shell fragments 194-195 

Same 209-210 

Limestone, light gray, granular 220-222 

Limestone, light gray, porous 230-240 



306 



GEOLOGIY AND GEOUND WATERS OF FLORIDA. 

Log of the well of the Apalachicola Ice Co., at Apalachicola. 
[By George H. Whiteside.] 





Thickness. 


Depth. 


No record 


Feet. 

1 

39 

30 

18 

4 

108 

.4 


Feet. 
1 


Surface sands . 


40 




70 


UnknowB. 


88 


Gravel 


92 


Limestone; containing some blue marl 


200 


Rock, hard flinty 


200i 
375 


Marl, and white clay (?) 







The first water was encountered between 40 and 70 feet and two 
other supplies were obtained at about 96 and 115 feet. Water under 
sufficient head to flow at the surface was procured at 325 feet and at 
375 feet. A flow of about 40 gallons per minute of sulphur water 
was obtained at 375 feet from a bed of gravel. Although the well 
was continued to a depth of 450 feet no other water beds were 
encountered. 

WATER SUPPLY. 

Source. — The Pleistocene sands of Franklin County contain an 
abundance of soft water which is available for shallow weUs. Beneath 
these sands the limestones of upper Oligocene age ('^Sopchoppy 
limestone" and Chattahoochee formation) contain large quantities of 
water. The Vicksburgian limestones are also an excellent source of 
supply and they furnish good flowing wells on the low ground near 
the coast. The exact head of the water is somewhat uncertain, but 
flows may possibly be obtained as high as 25 or 30 feet above sea 
level; good flows, however, are certain only on low ground. 

Quality. — The Pleistocene sands yield soft water which is well 
adapted to all domestic and farm uses. The water from the upper 
Oligocene limestones is always hard, but it is generally regarded as 
satisfactory. The Vicksburgian limestones yield hard sulphur water, 
and some deep wells near the coast obtain water containing large 
quantities of salt that unfits it for ordinary use. 

Development. — Shallow wells ranging in depth from 8 to 30 feet are 
numerous and the water level is sufficiently near the surface to make 
pumping easy. In the vicinity of Apalachicola and Carrabelle several 
deep wells have been sunk, most of which furnish an abundance of 
satisfactory water, though one of the wells belonging to the city of 
Apalachicola encountered very strong salt-sulphur water unfit for 
ordinary use. The city water supply of Apalachicola is obtained] 
from a well 360 feet deep; like most water from the other deep wells, 
the water contains some sulphur but is extensively used throughoul 
the town. 



FEANKLIN COUNTY. 



307 



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308 GEOLOGY AND GROUND WATERS OF FLORIDA. 

General water resources of Franklin County. 







. -ui- 










cs,—..t^^^ *„« 


Shallow wells. 


Town. 


location. 


Source of water. 


mation. 


Depth. 


Supply. 


Quality of 
water. 


Apalachlcola..- 
Carrabelle 


Plain 


■ 

Driven and drilled wells, pub- 
lic supply. 
Driven, drflled, and dug wells. 


"Pleistocene 

sand. 
do 


Feet. 
8-90 

16^30 


Large . 
...do... 


Soft. 


Sand dunes.. 






Deep wells. 


Av- 
erage 
thick- 
ness 
of 
sand. 


Depth 
to 

water. 


In- 
crease 
or de- 
crease 

of 
supply. 




Town. 


Depth. 


Supply. 


Head 

(above 

sea). 


Quality of water. 


Sewerage system. 


Apalachicola... 
Carrabelle 


Feet. 
365 
265 


Large... 
do 


Feet. 

15 ± 


Salt and sulphur 
Sulphur... . 




Feet. 


Feet. 
2- 5 
10-15 


None.. 
...do... 


Small. 




50± 


None 















GADSDEN COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Gadsden County occupies a large area between Apalachicola and 
Ochlockonee rivers in the northern part of the State. Its surface is 
a deeply dissected upland, which over extensive areas rises more 
than 250 feet above sea level and at Gretna is slightly more than 
300 feet in altitude. Along Ochlockonee and Apalachicola rivers 
well-defined terraces generally more than a mile in width rise 40 to 
100 feet above sea level. 

GEOLOGY. 

Gray sand of Pleistocene age covers the lowland, and gray or pink 
residual sand mantles the upland. Beneath this sand are yellow 
and red sands and sandy clays, which are referred to the Lafayette ( ?) 
formation and are underlain by sand, clay, and fuller's earth beds 
belonging to the Alum Bluff formation. The Chattahoochee under- 
lies the Alum Bluff formation and rests on Vicksburgian limestones. 
All these formations occur beneath the uplands, but in the stream 
valleys some of them have been eroded away. Thus on the western 
border of the county Apalachicola River has removed all the younger 
formations and has cut deeply into the Chattahoochee formation, 
and on the eastern border Ochlockonee River has removed all forma- 
tions younger than the Alum Bluff. Many of the smaller streams 
have cut their valleys through the Lafayette ( ?) formation and into 
beds belonging to the Alum Bluff formation. 

The average thickness of the Pleistocene sands is probably less 
than 5 feet and locally is only a few inches. In some places the Lafa- 
yette ( ?) formation may be more than 50 feet thick, but its average is 



GADSDEN COUNTY. 309 

• 

probably less than 30 to 40 feet. The thickness of the Alum Bluff 
and Chattahoochee formations has not been accurately determined^ 
but each of them probably exceeds 100 feet. At Quincy the Vicks- 
burgian limestones were reached at a depth of less- than 490 feet, 
and there was no indication that the base of the limestone had been 
reached at a depth of 1,001 feet. 

Partial log of the well of the Owl Commercial Co., at Quincy. 

Feet. 

Quartz sand, fine to coarse, white 101 - 449 

Clay, yellow 110 

Limestone, white, soft, sandy, or marl 118 - 123 

Clay, light brownish 131^- 154 

Limestone, soft, white, light gray, and greenish; lots of fossil 

shells 191 - 200 

Limestone, hard, light brownish; lots of shells 200 

Limestone, soft, white, and greenish clay 200 - 210 

Clay, dark brown 260 - 263^ 

Quartz sand, medium white; bits of limestone and dark- 
brown clay 

Sand, coarse, light gray, or greenish, limy, or soft sandy 

limestone 284 - 287 

Limestone, hard, porous, gray, and brownish 289 - 290 

Same; partly silicified 290§- 

Limestone, soft, porous, white 302 - 309 

Limestone, soft, light drab, sandy 315 - 316 

Limestone, soft, light drab 319 - 322 

Same 

Marl, gray, sandy 391 - 392 

Marl, light gray, sandy, or soft limestone 410 - 412 

Marl, light drab, or soft limestone 442 

Clay or soft shale, light gray and greenish, limy 453 - 454 

Limestone, porous, white 470 - 474 

Limestone, white and light, porous 476 - 480 

Limestone, hard and soft, light brownish 491 - 495 

Same; fragments of shells and coal (?) 495 - 505 

Same 506 - 507 

Same; hard layer, more or less crystalline 508 - 529 

Limestone, brown, porous, sugary looking 562 - 566 

Same 566 - 574 

Limestone; white and light brownish; made up of bits of 

shells, Bryozoa and Nummulites 576 

Same; white and light brownish 591 - 593 

Limestone, light brown, porous, sugary looking; denser and 

gray in places 618 - 625 

Limestone, light brown, porous, sugary 623 - 637 

Limestone, light brownish, porous 672 - 680 

Limestone, light brownish 693 - 699 

Limestone, white; with numerous fragments 699 - 704 

Same; with Orbitoides (?) 705 - 713 

Limestone, porous, light brownish 728 

Same; with Orbitoides (?); has siliceous strata 749 - 755 

Same; with bits of shells, Bryozoa, and Nummulites 755 - 766 



810 GEOLOGY AND GEOUND WATERS OF FLORIDA. 

Feet. 

Limestone, light brownish 781 

Bits of Bryozoa 800 

Limestone, soft, brownish; with brown chert 827 - 840 

Limestone, light brownish 859 - 865 

Same; with Bryozoa 876 - 881 

Same; gray, limy shale 905 

Limestone, light brownish 952 - 962 

Limestone, light brownish; with bits of shells and Bryozoa. . 983 -1, 001 

From 491 to 529 feet belongs to the Orbit oides zone of the Vickg 
burgian, as shown by Bryozoa determined by Bassler. 

WATER SUPPLY. 

Source. — Good water should be obtained from all the geologic! 
formations in Gadsden County, though the Pleistocene sands arej 
usually too thin to be important, and the water capacity of several 
of the other formations has not been satisfactorily determined. 
Most of the shallow wells obtain water from the Lafayette ( ?) forma- 
tion, though a few of them may penetrate the Alum Bluff. The] 
Chattahoochee will supply an abundance of water at most localities,] 
and the Vicksburgian limestones will yield very large quantities foi 
deep wells. 

Quality. — ^The water from the Lafayette ( ?) formation is usually 
soft, though locally it may be moderately hard. The older formations, 
as a rule, yield only hard water, but at some localities the water 
obtained from the Alum Bluff formation may be soft. The water 
from the Vicksburgian limestones may also be sulphurous and at Chat- 
tahoochee it is saline. 

Development — In Gadsden County good supplies of soft water may 
usually be obtained by wells less than 50 feet deep, but the sanitary 
quality of this water may be questionable where the wells are located 
near buildings. Many wells range from 50 feet to somewhat more 
than 100 feet in depth, and these are regarded as more desirable 
than the shallower wells; because most of the water beds are covered 
by one or more layers of clay, which exclude surface water. Wells 
exceeding 200 feet in depth have been drilled at Havana, Chatta- 
hoochee, and Quincy. The deeper wells at Quincy yield sulphur 
water and the water from the deep well at Chattahoochee is saline. 
However, the water obtained by the deep wells at Quincy can 
be used, and that from the well at Chattahoochee has improved since 
the well was first drilled. (See PI. XVI, A, p. 230.) 



GADSDEN COUNTY. 



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312 



GEOLOGY AND GKOTJND WATERS OF FLORIDA. 

General water resources of Gadsden County. 





Topographic 
location. 


Source of water. 


Surface for- 
mation. 


Shallow wells. 


Town. 


Depth. 


Supply. 


Qual- 
ity of 

water. 


Chattahoochee . . 


Hillv.... 


Dug and bored wells 

Bored and dug wells 

Bored and driUed wells 

Bored and two driven wells. 

Public supply, dug and 

drilled wells. 
Dug and one drilled well. . . 


Pleistocene.... 
Lafayette (?).. 


Feet. 
35-40 
15-50 

'45^75" 

25-95 

15-50 


Good 

SmaU.... 

...do 

...do 

...do 

Moderate 


Hard. 


Concord 

Hanson 


So 

do 

Level h i g h - 

land. 
HiUy, relief 

100 feet. 
HiUy 


Soft. 
Do. 
Do. 


Qulncy 


Lafayette (?).. 

Pleistocene 
and Lafa- 
yette (?). 


Do. 


River Junction.. 


Hard. 











Shallow wells. 


Deep wells. 


Average 
thickness 
of sand. 


Sewerage 
systems. 


Depth to 
water. 




Town. 


Principal 
water bed. 


Depth. 


Supply. 


Remarks. 


Chattahoochee 


Marianna 
limestone, 
do 


Feet. 




Feet. 
40+ 

50± 


None.... 

...do 

..do 


Feet. 
-10-15 

Few. 

Few. 
Few. 




Concord 


50 

280 

266 

600-1,001 

86 




Supply varies with 
weather. 


Hanson 


. do 


Large . . 


Havana 


do 






...do 




Quincy 


do 


Large . 




Yes . 


Deep wells head 70 
to 100 feet above 
sea. 

Sulphur water. 


River Junction.. 


do 






None.... 


Few. 











HAMILTON COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Hamilton County comprises an area less than 20 miles in average 
width, bordering the Georgia line for a distance of over 40 miles. The 
surface is generally rolling and well drained, but in the vicinity of 
Jasper and toward the northwest corner sink holes and other depres- 
sions give rise to lakes and swamps. Octaha tehee Lake near the 
northwest corner lies in a depression formed by the solution of lime- 
stone and drains through a sink into an underground channel. Dur- 
ing dry seasons nearly all of the water escapes, leaving only a small 
pond in the lowest part of the basin. 

Except in a narrow belt along the streams, the surface of the county 
is more than 100 feet above sea level, and a large tract of land in the 
central part of the county is more than 150 feet in altitude. 

GEOLOGY. " 

The lowlands of Hamilton County are covered by a thin mantle 
of gray Pleistocene sand and the uplands by a thin layer of residual 
sand underlain by red and yellow sands and sandy clays which are^ 



HAMILTON COUNTY. 313 

referred to the Lafayette (?) formation. At White Springs the 
surficial sands and clays rest on blue and gray sands, clays, and 
marls belonging to the Alum BluflP formation. The Alum Bluff 
extends northward into Georgia and is an important source of water 
in the eastern part of the county. 

Another important water bed, which is exposed at White Springs, 
is the Hawthorn formation. It consists of sands and sUicified lime- 
stones belonging stratigraphically below the Alum Bluff formation. 
Toward the western part of the county the Hawthorn formation is 
represented by the limestones exposed at Suwannee and these doubt- 
less extend northward to the State line. The Vicksburgian lime- 
stones underlie the entire county, but they are covered by younger 
formations. 

The light-gray or red sands that form a continuous mantle over the 
surface of the county are as a rule only a few feet thick. The under- 
lying red and yellow sands and clays probably average less than 30 
feet in thickness, though in places they reach a maximum of more 
than 50 feet. At White Springs the Alum Bluff formation is about 
100 feet thick, and at the same locality the thickness of the Haw- 
thorn formation is at least 25 feet. However, the Hawthorn forma- 
tion probably thickens toward the north and west. The Vicksburgian 
limestones are doubtless several hundred feet thick, but definite infor- 
mation concerning them is lacking. 

WATER SUPPLY. 

Source. — The sands of the Lafayette ( ?) formation yield considerable 
water of excellent quality and are probably much more extensively 
used than any other formation in the county. However, the under- 
lying Hawthorn and Alum Bluff formations are reached by many 
wells and are the most important water-bearing beds now beiQg 
exploited in the county. The sands of the Alum Bluff are important 
as a source of water in the eastern part of the county, but westward 
they appear to thin out, and the wells penetrate the limestones and 
sands of the Hawthorn formation. The Vicksburgian limestones 
would also yield an abundant supply of water and may possibly be 
penetrated by one or two of the very deep wells. 

Quality. — The water obtained from the shallow wells is soft, but 
that from aU the deep weUs is hard and some of it carries hydrogen 
sulphide. 

Development. — Wells 100 to 150 feet deep usually yield good supplies 
of hard water, but locally deeper ones have been sunk. Water 
usually rises to within 50 to 60 feet of the surface, though in a few 
localities it comes much nearer. At Jasper the well of the City 
Power Co. is reported to have a depth of 450 to 500 feet and to yield 



314 GEOLOGY AND GKOUND WATERS OF. FLORIDA. 

sulphur water. The well doubtless penetrates the Vicksburgian 
limestones, and it would be possible to sink wells to these rocks in 
any part of the county. They will supply a large amount of water^ 
but it is doubtful if the head would be so great as in the shallow wells. 
Springs are numerous and some of them are large. The most impor- 
tant is White Spriag, on the bank of the Suwannee, which boils up 
through a large circular hole in the rock and forms a stream of mod- 
erate size. A pavilion has been built about the point of emergence. 
The water is used largely for bathing and driaking and is thought to 
have considerable medicinal value, especially in the treatment of rheu- 
matism and similar diseases. It contains a large amount of sulphur 
and other mineral matter such as lime and magnesia, together with 
smaller quantities of other inorganic material. The water probably 
comes from the Vicksburgian limestones and escapes at this locality 
because of a hole in the chert bed that caps the limestone. 



HAMILTON COUNTY. 



315 



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316 GEOLOGY AND GEOUND WATERS OF TLOEIDA. 

HERNANDO COUNTY. 
By G. C. Matson. 
GENERAL FEATURES. 

Hernando County lies in the western part of the peniosula, extend- 
ing from the Gulf coast east to Withlacoochee River. Near the coast 
the surface of the county is a low, nearly level plain, 20 to 25 feet 
above sea level. Along Withlacoochee River a terrace rising 40 to 60 
feet above sea level represents a former level of the river. It extends 
down the river, where it doubtless unites with a terrace bordering the 
coast. Remnants of a similar terrace with an altitude of 70 to 100 
feet may be seen at many points. The interior of the county is rolling 
and consists of high rounded hills interspersed with basin-shaped 
depressions or sinks. A few of these sink holes are occupied by lakes 
and ponds, but most of them are dry. The range in altitude between 
depressions and hills frequently amounts to over 100 feet, and the 
hiUs themselves may rise to nearly 200 feet above sea level. The 
sink holes were formed by the breaking down of the roofs of caverns, 
and they bear testimony to the great extent of the underground 
drainage . Throughout the upland portion of the county nearly all 
the rainfall passes to the underground channels in the limestone. 

GEOLOGY. 

The terraces in Hernando County are covered by a thin deposit of 
gray Pleistocene sand and the uplands by a thin coating of gray or 
yellow residual sands. 

In the vicinity of BrooksviUe and in the southeastern part of the 
county the sands are underlain by limestones, sands, and clays 
belonging to the Hawthorn and Alum Bluff formations. The 
exact distribution of these formations in Hernando County has not 
been determined in detail, but small deposits are known to occupy 
many of the higher hiQs. The Vicksburgian limestones are the sub- 
surface formations over a large part of the county; they underlie 
the Hawthorn where that formation is present and doubtless reach 
the surface in some of the streams near the western edge of the 
county. They are exposed in most of the phosphate mines. 

The gray residual sand probably averages less than 5 feet in thick- 
ness, but locally the sands of Pleistocene age may attain 25 to 30 feet. 
The yellow sands are commonly from 20 to 30 feet thick, though 
locally they are much thinner and in some places are entirely wanting. 
The thickness of the Alum Bluff formation has not been ascertained 
and that of the Hawthorn formation is difi&cult to determine; in 
the vicinity of BrooksviUe the latter may exceed 100 feet, but at many 



I 



HERNANDO COUNTY. 317 

places in the county it is represented by only a few feet of hard cherty 
limestone. The Vicksburgian limestones doubtless attain a thick- 
ness of several hundred feet in Hernando County. 

WATER SUPPLY. 

Source. — There are only two important water-bearing formations 
in Hernando County — the surficial sands and the Vicksburgian 
limestones. The sands are important sources of supply for many 
shallow wells, and the limestones are penetrated by nearly all of the 
deep ones. Both formations yield an abundance of water, and the 
supplies from both are extensively utilized. 

Quality. — The sands furnish soft water. The deeper supplies are 
hard, but they are regarded as satisfactory for all purposes. 

Development. — Shallow wells usually obtain water within a few feet 
of the surface and the supplies are ample for the needs of a family or 
for farm use. The water is easily raised either by small suction pumps 
or by the old-fashioned bucket. The greatest objection to the use 
of these wells is the difficulty of excluding impure surface water. 
The deep wells of Hernando County range from about 75 to 280 
feet and many of them are less than 150 feet. They secure large 
quantities of water suitable for domestic or industrial uses. 

Springs are numerous and some of them are of considerable size. 
Weekewachee Spring, 8 miles southeast of Bay Port, has an estimated 
flow of 100,000 gallons per minute and gives rise to a good-sized 
stream. A small sulphur spring, 2 miles northeast of Bay Port, has 
an estimated flow of 10,000 gallons per minute. Neither of these 
springs is used. 



318 



GEOLOGY AND GKOUND WATERS OF FLOKIDA. 















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HILLSBOEOUGH COUNTY. 

General water resources of Hernando County. 



319 





Topo- 
graphic 
location. 


Source of 
water. 


Surface formation. 


Shallow wells. 


Town. 


Supply. 


Quality of 

water. 


Principal 
water bed. 


Brooksville 


HiUy 

RoUing.... 


WeUs... 
...do 


Clays 


Good.... 


Partly soft.... 




Croom 


Sand 


Do. 


Istachatta 








Do 



















Deep weUs. 


Depth to 
rock. 


Depth to 
water. 


Sewerage 
system. 


Town. 


Depth. 


Supply. 


Head 
above sea. 


Quality 
of water. 


Brooksville . . 


Feet. 
226 
75 


Abundant. 

...do 

...do 


Feet. 
18-20 


Hard 

...do 

do 


Feet. 
0-100 


Feet. 


None 


Croom 


15-20 


Do. 


Istachatta 


Do 



















Springs of Hernando County: 



Name. 


Owner. 


Nearest post 
office. 


Direction and 
distance. 


Discharge 
per minute. 


Topographic! 
surroundings . 


Emergence. 


Weekewachee. . 
Sulphur 


Wilden and 

McClure. 
S.V.Varn 


Bay Port... 
do 


8 miles south- 
east. 

2 miles north- 
east. 


Gallons. 
100,000± 

10, 000 ± 


Sandy scrub. 


Boils. 








Name. 


Geologic source. 


Quality 
of water. 


Tempera- 
tui-e. 


Nature of stre.a,Tn . 


Remarks. 


Weekewachee. . 
Sulphur 


Oligocene lime- 
stone. 


Hard.... 


"F. 

78 


Small stream 12 
miles to Gulf. 


No improvements; spring 
not used. 
Do. 










G 


ulf. 







HILLSBOROUGH COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Hillsborough jCounty comprises a large area on the Gulf coast. 
Tampa Bay extends a long distance into it, forming an excellent 
harbor. West of this bay a broad peninsula rises to a maximum 
height of over 50 feet. A series of low islands border the coast and 
inclose narrow sounds of shallow water. 

East and north of Tampa the surface becomes gently rolling, but 
toward the southeast it is generally flat and locally swampy. A 
broad terrace borders the coast and extends along Hillsboro River. 
Near Tampa this terrace is hardly more than 20 to 25 feet above sea 
level; another terrace along the river lies at an altitude of 40 to 60 
feet at Thonotosassa ; and a still higher one probably occurs in Hills- 
borough County, but it has not yet been discriminated. 
76854°— wsp 319—13 21 



320 GEOLOGY Al^D GKOUIirD WATERS OP FLORIDA. 

GEOLOGY. 

The lowlands of Hillsborough County are coYered by gray sand of 
Pleistocene age, locally underlain by red and yellow sands and clays 
derived from decomposition of the underlying rock. The uplands 
have a coating of gray or light-yellow s#id of residual origin. 

Near the southeast corner of the county an area is underlain by 
land-pebble phosphates belonging to the Bone Valley gravel. This 
formation is extensively developed in the eastern part of the county, 
and is much less important here than in the adjoining portion of Polk 
County. Beneath the Bone Valley gravel are phosphatic limestones, 
sands, and clays belonging to the Alum Bluff formation. The 
Tampa formation underlies the entire surface of the county, resting 
unconformably upon the soft porous Vicksburgian limestones. 
These limestones are not exposed in Hillsborough County; in the 
northern part they are buried beneath 100 to 150 feet and in the 
southern part probably by a still greater thickness of younger rocks. 

The average thickness of the Pleistocene gray sands is probably less 
than 25 feet, and the light-colored residual sands and clays are thin. 
The thickness of the Alum Bluff formation could not be learned. 
The Tampa formation is thought to attain a maximum thickness of 
somewhat more than 130 feet. As there are no good sections, a large 
portion of this formation is known only from well logs. The most 
satisfactory log is that of the well at the Tampa waterworks (p. 106). 
The Vicksburgian limestones probably attain a thickness of several 
hundred feet, but no information is available concerning the exact 
depth to the base of these formations. The following sections show 
thicknesses at the points named: 

Log of E. C. Stewart's well at Plant City. 



Depth. 



Subsoil 

Sand 

Clay, white; with phosphate rock 

Clay, yeUow; with phosphate rock 

Shellrockjhard 

SheUrock, harder 

Flintrock, hard 

SheUrock ."i 

Rock, hard 

SheUrock, porous; considerable water 

SheUrock, harder 

Rock, harder, apparently containing smaU water-bearing cavities . 




HILLSBOEOUGH COUNTY. 

Log of the city well at Plant City. 



321 



Soil 

Clay, red; changing gradually to white 

Clay, white; with smaU pebbles; phosphate 

Marl 

Shell rock, hard 

Shell rock, as in soft layer 

SheU rock, hard 

Shell rock, much harder, flinty 

Sand, loose, fine 

Shell and soft rock . in alternating layers 

Shell rock, with a lew phosphatic pebbles 

Quicksand, loose 

Shellrock, hard 

Shell rock, hard; some layers contain hard flint 
Cavity with an especially good supply of water 



Log of the well at Fort De Soto. 
[From samples of drillings furnished by S. W. Bryan.] 




Sand, fine, white; fragments of shells 

Sand, mixed fine white and dark colored; with fragments of shells 

Sand, dark gray to greenish gray; partly consolidated 

Limestone, dense, gray, porous; containing some shells 

Ilitnestone, dense, gray, and granular gray sandstone; numerous shells 

Limestone, light gray, porous 

Limestone, mixed light and dark gray 

SheUs and shell fragments 

Limestone, dense, dark gray 

Marl, fine grained; a few shell fragments 

Limestone, dense, dove-colored 

Limestone, fine, white 

Limestone, light dove-colored 

Marl, thin, granular; containing sand 

Sand, pale yellow 

Limestone, granular, light gray 

Sand, fine, gray, gray graniilar limestone, and wine-colored silex 

Marl, fine, gray, sandy; with wine-colored silex 

Limestone, fine, gray, sandy 

Sand, light gray 

Limestone, porous, white 

Limestone, coarse grained, gray 

Limestone, yellowish gray ; containing some chert 

Limestone, gray ; containiBg chert 

Chert, dark gray 

Limestone, light gray 

Limestone, white 

Limestone, pinkish gray 

Limestone, very fine grained, dense, white ■ 

Limestone, coarse grained, brownish gray 

Limestone, light gray 

Limestone, medium grained, light gray 



To judge from the samples^ many of those below 200 feet contain 
material that has fallen from above, and the absence of character- 
istic fossils, together with ^this mixing of materials from various 
levels, makes it difficult to determine the thickness of the various 
formations. From the conditions at Tampa it is believed that this 
well penetrated a considerable depth into the Vicksburgian limestones. 
The wine-colored chert encountered between 240 and 260 feet should 
belong to the Tampa formation and represent the bed exposed at 
Ballast Point, but this would indicate a remarkably steep dip for 
Florida, and possibly the chert has fallen from a higher horizon. 



322 GEOLOGY AND GKOUKD WATEES OF FLOKIDA. 

WATER SUPPLY. 

Source.- — The surficial sands contain an excellent supply of soft 
water which may be obtained within a few feet of the surface. The 
Bone Valley gravel is not important as a water-bearing formation. 
The Alum Bluff and Tampa formations contain considerable quanti- 
ties of water but have no persistent layers of porous rock and the 
occurrence of water is somewhat uncertain. The Vicksburgian lime- 
stones are the most important source of supply and contain an 
abundance of water that may be obtained by drilling from 100 to 
200 feet, except on the uplands and in the southern portion of the 
county, where the depth to good water-bearing beds is greater. 

Quality. — The water from the surficial sands is usually soft and 
is regarded as satisfactory. That from the Alum Bluff and Tampa 
formations is hard water but is suitable for domestic or industrial 
uses. The Vicksburgian limestones supply hard sulphur water. In 
most localities this water is usable, but in a few places it is too highly 
mineralized. Deep wells at the power house of the Tampa Electric 
Co. yield strongly saline water. However, such supplies are rare 
and the water from the Vicksburgian limestones is usually better 
than that from the other formations because there is less danger of 
its becoming polluted by impure surface drainage. 

Development. — Shallow wells usually obtain ample supplies within 
50 feet of the surface and many of them do not exceed 10 to 15 feet 
in depth. A few have been drilled to depths of over 100 feet, passing 
through good aquifers in the sands and entering the underlying lime- 
stones. Most of the deeper wells go down for 100 to 200 feet, though 
a few have been sunk for several hundred feet. The deepest well 
reported is 3 miles southeast of Plant City and is owned by the 
Coronet Phosphate Co. It is 1,100 feet deep and will supply over 
1,000 gallons per minute. Deep wells have been sunk in Tampa, but 
it is seldom necessary to drill to more than 250 feet. Flowing 
weUs may be obtained on low ground near the coast at St. Peters- 
burg, Tampa, and Ybor City. A small flow has also been procured 
at Dunedin. At St. Petersburg and Tampa the flows are obtained 
from the Vicksburgian limestones, but at Dunedin the water probably 
comes from the Tampa formation. An unsuccessful attempt was 
made to obtain a flowing well at Clearwater, a well being drilled 740 
feet without encountering water that would rise to the surface. How- 
ever, no attempt was made to case this well so as to test the head of 
the water from the different aquifers, which were encountered at 85, 
250, and 350 feet. The water from a depth of 85 feet rose to about 
sea level and the supplies from the lower beds did not show any 
great increase in head, but this may have been due to the fact that 
the water from the deeper beds escaped through the porous layer at 

















ead- 


Depth 

to 
rock. 


Depth to 
principal 
supply. 


Quality of water. 


Depth 
of 

second 
sup- 
pUes. 


Yield per 
minute. 




Above 
e or 
below 
surface. 


Remarks. 


Feet. 
.. -76 
.. -43 
.. -25 


Feet. 


Feet. 




Feet. 


Gallons. 






50 
70 
75 ± 
52 
41-43 
74 
120 


Hard.. . 


40 

12 

36- 

36- 

38- 

15 


Several. 

Several, 

Several. 

200 




do 




do 




L. -26 
.. -26 
. -18 
. -24 
- + 1- 


26" 


do 




do 




do 


Many. 

Several, 

Few. 

Many. 

Few. 

500 

1,010 




do 




Sulphur, slight 




Flow. 






do 






. -33 

. -39 
. - 9 

. -31 

. + 1 

' / Se\^- 
• ■ \ eral. 

.- + 
+ 




55 
340 


do 






Sulphur.. 






do 
























Many. 




40 
165 


176 
176 


Hard.. 






Soft . 


None. 


60 






Not completed. 
Typical well of the city. 
Forms scale in boilers. 


} 


25 








Sulphur 




1,500 
8 






do.. . 








130 




400 




. + 




Sulphur 


100 
93 

Many. 
Many. 
Many. 








Sulphur, slight 






. - 2 

i: -2^2 






Sulphur 




Do. 






do 




Do. 










Abandoned. 


























130 


Hard and sulphur 

Sulphur, slight 

do 


130 ± 
168-182 




Drill dropped 5 feet when it 
struck hard water; sul- 
phur water encountered 
below. 


108 
214 
250 














192 


do 


97-116 










t 






Sulphur, slight 




50 
225 
150 


9 of these 11 wells are used 








do 


150 


for pubhc supply: 2 are 
held in reserve. 








do . 








.:...do 













do 




200 










do 












do 














do 




80 

Several. 

Few, 

Few. 

Many. 

4U0 

400 

Several. 

Many. 

Several, 
Several. 




. +2 
. -31 
. -37 


20 


200 

78+ 








. .do. 






do 










.do. 




Forms scale in boilers. 


- +1 

- +1 

+ 




350 
At bottom. 


Sulphur and salt 

.do 


300 ± 
300± 


Flows at high tide. 
Do. 




Forms scale in boilers. 






.. .do 






,. -10 
i- -16 






do 










.do 








150-160 

150 
150 
55 
100 




160+ 




. -3 

r Si 

. -21 
. -21 
. -16 

. -7 

- +1 

^. -5 
. -2 

. -5* 

- +3" 
. -20 

. -4 

. -7 
. -7 

. -7 




do 


300 




.do... . 










80 

80 

80 

Many. 


















375 
175 ft. below. 


Hard . 






Sulphur 






. .do 




Few. 

Many. 
Many. 

Many, 

Few, 

Few, 

Several. 


Do. 




125 


do 




Do. 


do 




Do. 





98 

50+ 

45+ 


. ..do 




Do. 


do 






Hard 






Sulphur; slight salt 




2 wells. 














All way 

down. 

125 ft. and 

below. 


do 








do 
















a 


Filled t 


400 feet. 











Typical wells of Hillsborough County. 



1} miles nortl 
IJ miles nortt 
1 mile north.. 



Buay Fegel 

M.H. Plant 

H. W. Bachman.. 
Clearwater Ice Co.. 



City 

Coronot Pliosp 



City waterworks.. 



Read. ... 
Pickney.. 



Tampa formation. 



TamijaleeCo E.W.Smith.. 

do do 

Talder-Mcl^eod Lum- Abner Powell. 




-■wsp 319-13. (To taco page 322.) 



> Wausr-Supply Paper li. S. Geol. Survey No. 102, p. 2 



HILLSBOROUGH COUNTY. 323 

85 feet. The water obtained at 250 feet contained sulphur and that 
at 350 feet was a very strong brine. The most favorable location 
for flowing wells at Clearwater is on low ground, as the water from 
the Vicksburgian limestones at St. Petersburg and Tampa does not 
rise high above sea level and its head would probably be slightly 
lower at Clearwater. Flowing wells should be obtained on the low 
ground near the shores of Tampa Bay, and the head will probably 
be greater near the southern end of the county than it is at Tampa. 

Hillsborough County contains excellent springs, the most impor- 
tant being Tampa Sulphur Spring and Green Spring (Espiritu Santo 
Spring) . Both of these springs are used as centers for resorts and are 
supplied with hotels and bathhouses. The Tampa Sulphur Spring 
emerges from a hole in the limestones of the Tampa formation and has 
a very large flow. At Green Spring there are several points of emerg- 
ence and the flow is small ; the water is highly charged with sulphur 
and salt and is thought to have medicinal properties. Near Beileair 
a small spring which emerges in the edge of the bay has been sur- 
rounded by a concrete wall and is pumped to the Beileair Hotel, 
where it is used for drinking. 

Beileair has a public water supply taken from a small lake. The 
water is used chiefly for the Belle view Hotel and is very satisfactory. 
The public supplies at Plant City, Clearwater, Tampa, West Tampa, 
and Tarpon Springs are all obtained from wells. The waterworks 
at Plant City is supplied by a single well penetrating the Vicks- 
burgian limestones. At Clearwater three wells ranging in depth 
from 52 to 80 feet draw from the Tampa formation ; the quantity of 
water is ample and the quality satisfactory for all general purposes 
At Tarpon Springs three wells, ranging in depth from 65 to 105 feet, 
probably draw from the Vicksburgian limestones. The West Tampa 
water supply is obtained from wells and is ample for the needs of the 
city. The Tampa Waterworks Co. has 11 wells ranging in depth 
from 180 to 328 feet, but only 9 of them are in use; tests to determine 
their yield indicate that the limestones at that locality contain very 
large quantities of water. At St. Petersburg the public supply is 
obtained in part from wells and in part from a lake; the system is 
capable of furnishing a very large amount of water of excellent 
quality. 



324 GEOLOGY AND GROUND WATERS OF FLORIDA. 

General water resources of Hillsborough County. 





Topo- 
graphic 
loca- 
tion. 










Surface for- 
mation. 


Shallow wells. 


Town. 


Source of water. 


Depth. 


Supply. 


Quality of 
water. 


Principal 
water bed. 


Clearwater 


Plain.. 

...do.- 
...do... 

...do.„ 


Drilled and driv- 
en wells. 

Driven wells 

Driven weUs and 

springs. 
Public supply . . . 

Driven and 
driUed wells. 

Driven wells and 
cistern. 

Public supply; 
drilled and 
driven wells. 
do 

Driven and 
driUed weUs. 

PubUc supply; 
driven and 
drilled wells. 


Pleisto- 
cene and 
residual 
sand. 

...do 

...do 

Pleistocene 

sand, 
.-do 

...do 

...do 

...do 

...do 

.-do 


Feet. 
12-120 

35-125 
20-47 


Ample 

...do 

...do 


Soft 


" Peninsular " 


Dunedin 

Espiritu Santo 

(Green Spring) 

Nichols 


...do 

...do 


Umestone. 

Do. 
Do. 

Do. 


Plant City 


...do-. 
...do— 
...do... 

...do.- 
...do.- 

...do... 


10- 75 ± 
25-50 
15- 70 

15-100 
30- 60 

30-100 


Ample 


Soft 


Do. 


Port Tampa 


Very hard. 
Soft 


Do. 


St. Petersburg.. 


Moderate.. 

Ample 

...do 

...do 


Do. 


Tampa 

Thonotosassa . . 

West Tampa. . . 


...do 

...do 

...do 


Do. 
Do. 

Do. 




Deep weUs. 


Aver- 
age 
thick- 
ness 
of 
sand. 


Depth to 
water. 


Sewerage 
system. 




Town. 


Depth. 


Supply. 


Head 

above 

sea. 


QuaUty of 
water. 


Remarks. 


Clearwater 

Dimedin 


Feet. 
700± 


Large. 


Feet. 


Sulphur 


25-35 
10-30 

10± 


10-20 
30± 

12 

30 
Several. 
...do.... 


None 

-<i« 

...do 

...do 

. do . 




Espiritu Santo 

(Green Spring). 

Nichols 










near town. 


30 
300-600 






£ 






Plant City 


...do... 


-33 




o± 




Port Tampa 




(i 




charges 
to sea. 


Water very poor 
and cisterns chief 
source of supply. 


St. Petersburg.. 
Tampa 


90-430+ 
100-350+ 
380 


Large. 
...do... 
...do... 


10+ 
15-20 


Sulphur 

Some salt in 

deep wells. 

Hard 


Few. 

2-30 

12-20 
30± 


...do.... 


Dis 

in 

Ye 


Thonotosassa . . 


26-50 
15-18 


None 




West Tampa. . . 


do 
















deep salt 
wells. 













Springs of Hillsborough County. 



Name. 


Owner. 


Nearest 
post office. 


Direction 

and 
distance. 


Dis- 
charge 
per 
min- 
ute. 


Topo- 
graphic 
surround- 
ings. 


Use. 


Emergence. 


BeUeair Spring.... 

Espiritu Santo or 
Green Spring. 

Tampa Sulphur 
Spring. 


M.H.Plant 

Capt. L 
Tucker. 

Jo s iah 
Richards. 


BeUeair... 

Safety 
Harbor. 

Tampa. . . . 


1 mile 
south. 


Gallons. 
3,000- 
4,000 
20 

65, 000 


Plain 

...do 

...do 


Drinking.. 

Hotel and 
bath- 
house. 

Clubhouse, 
hotel, 
swim- 
ming 
pool. 


Boils up a 
edge of sea. 

Boils up ai 
edge of bay. 

Boils up froD 
hole. 


6 miles 
north. 



HOLMES COUNTY. 
Springs of Hillsborough County — Continued. 



325 



Name. 


Source 

of 
water. 


Surface for- 
mation. 


Varia- 
tion 
in 
flow. 


Improve- 
ments, 


Quality of 
water. 


2 
s 

1 

Eh 


Trade name of 
water. 


Remarks. 


Belleair 


Sand.. 

...do... 

Lime- 
stone. 


Tampa for- 
mation. 

do 

Oligocene.. 


Slight. 
None.. 
...do... 


Hotel 

Clubhouse 
and hotel. 

do 


Sulphur, 

Sulphur 
and salt. 

Hard.... 


'F. 




No contamina- 


Spring. 

Espiritu 
Santo or 
Green 
Spring. 

Tampa SiU- 
phur Spg. 


74 
72 


Green Springs 
Water. 


tion near. Not 
muddy after 
rains. 
Do. 

Do. 







HOLMES COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Holmes County borders the Georgia line, extending from Holmes 
Creek westward some distance beyond Choctawhatchee River. Its 
surface consists of rolling uplands which locally rise to altitudes of 
more than 250 feet. All the large streams are bordered by broad 
terraces of level land, which merge with other terraces along the 
coast. Extensive swamps lie along some of the streamy and smaller 
ones occur in many localities. 

GEOLOGY. 

Gray sands of Pleistocene age form the surface deposits on the 
terrace in Holmes County, and the uplands are covered by light- 
colored residual sands, through which outcrop red and yellow sands 
and sandy clays belonging to the Lafayette ( ?) formation and rocks 
of other underlying formations. In a large portion of the county 
the Lafayette ( ?) formation is underlain by the Alum Bluff forma- 
tion and this formation rests on the Chattahoochee. In the valleys 
of some of the streams near the northern boundary the Vicksburgian 
limestones immediately imderlie the surficiaj sands, but elsew^here 
these limestones are buried beneath the Chattahoochee and younger 
formations. 

The residual sands are comparatively thin, probably averaging 
less than 5 feet, though locally they may amount to several feet. 
An average thickness of 30 feet is probably a fair estimate for the 
gray sands of Pleistocene age, and the Lafayette (?) formation, 
though locally these may reach a maximum of over 50 feet. The 
Chattahoochee may have a maximum thickness of over 200 feet, 
though over a large part of the county it is probably much thinner. 
The thickness of the Vicksburgian limestones is imdetermined. 



326 



GEOLOGY AND GKOUND WATEES OF ELOEIDA. 



WATER SUPPLY. 

Source. — The Pleistocene sands are not important water beds 
except where they are unusually thick, but the Lafayette ( ?) forma- 
tion contains an abundance of water available for shallow wells. 
Valuable water beds occur in the Alum Bluff, Chattahoochee, and 
Vicksburgian formations. The Vicksburgian limestones are the best 
source of water because they contairi very large supplies that may 
be easily pumped. 

Quality. — The surficial sands contain, soft water. Both the Chatta- 
hoochee and the Vicksburgian limestones supply hard water but are 
subjected to so much less danger of pollution that their waters are 
usually more desirable than those from the surficial sands. 

Development. — In Holmes County shallow wells usually obtaia 
ample supplies of soft water within 10 to 35 feet of the surface. Only 
two deep wells are reported; the Sessons-Whited Co.'s well found 
an abundant supply of hard water at the bottom in Vicksburgian 
limestone at 398 feet; and James Williams's well at Eleanor obtained 
an excellent supply from the same limestones at 275 feet. 

Typical wells of Holmes County. 



Nearest 

town or 

post 

office. 



Direction 

and 
distance. 



Owner. 



Driller. 



Date 
sunk. 



Surface 
forma- 
tion. 



Geologic 
source. 



Type 
of well. 



Use. 



Bonifay. 



Eleanor. 



I mile 
south. 



S e s s n s- 
Whited Co. 



Jas. Williams 



F. J. White 
& Co. 



.do 



1906 



Pleisto- 
eene. 



.do..... 



Vicksburg- 
ian lime- 
stone. 

-...do 



Drilled 



.-do... 



Boilers and 
drinking. 

Do. 



Nearest town or 
post office. 









ii 


-t^ 


Qual- 


5'^ kT 


u 




i 


i 




in 


ity of 
water. 




2| 


ft 


« 


^ 


W 






ft 


Feet. 


In. 


Feet. 


Feet. 


Feet. 




Feet. 


Gallons. 


398t 


8 


170± 


10± 


398 


Hard.. 


100+ 


125 


275 


6 


275 


30 


275 


...do... 


219 







Remarks. 



Bonifay. 
Eleanor. 



Forms scale in 
boilers. 



General water resources of Holmes County. 





Topo- 
graphic 
location. 


Source of water. 


Surface for- 
mation. 


Shallow wells. 


Town. 


Depth. 


Supply. 


Quality of 
water. 


Principal 
water beds. 


Argyle.... 


Hilly.... 

...do 

Plain..-. 

...do 


Dug and driven 
wells. 

Drilled well 


Pleistoce n e 
sand and 
L a f a - 
yette (?). 

do 


Feet. 
17-22 

15-35 
12-25 

12-26 


Good.. 

...do... 
...do... 

...do... 


Soft 

Hard 

Soft, some 

hard. 
...do 


Marianna 


Eleanor 


limestone. 
Do. 


Ponce de Leon. 
Westville 


Dug and driven 

wells and springs. 

do 


Pleistocene 

sand. 
do 


Do. 
Do. 



JACKSON COUNTY. 

General water resources of Holmes County — Continued , 



327 



Town. 


Deep wells. 


Average 
thiclmess 
of sand. 


Depth to 
water. 


Increase or decrease 
of supply. 


Sewerage ' 


Depth. 


Supply. 


system. 


Argyle . . 


Feet. 




Feet. 
20+ 
40+ 
25+ 
25+ 


Feet. 
10± 
10+ 
10 
6± 


Slight 


None. 


Eleanor 


275 


Abundant 


None 


Do. 






Slight 


Do. 


Westville 






do 


Do. 











JACKSON COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Jackson County is on the west side of Apalachicola Kiver in northern 
Florida. Its surface is generally rolling, but it has some flat areas and 
extensive swamps — as northwest of Gottondale and south of Cypress, 
for instance. There are also swamps and lakes in the northeastern 
part of the county. 

Wide areas of upland that rise oyer 150 feet above sea level have 
been eroded into a topography characterized by flat-topped hills 
and steep-sided valleys. Along all the large streams broad flat 
terraces represent former water levels. They widen toward the coast 
and finally merge with seaward-facing terraces which represent 
former extensions of the sea upon the margin of the land. 

The county is bordered by Apalachicola Kiver and Holmes Creek 
and is crossed by Chipola River. These streams receive the surface 
drainage through a number of small tributaries. The many sink 
holes in the region where the Vicksburgian limestones are near the 
surface indicate the existence of extensive underground channels, 
some of which, like the cavern near Marianna, are accessible. About 
6 miles north of Marianna a natural bridge spans Chipola River, but 
is submerged when the water is high, because the channel in the 
limestone is not large enough to accommodate all the water. 

GEOLOGY. 

The terraces of Jackson County are covered by gray sands of 
Pleistocene age. The uplands are underlain by red and yellow sands 
and sandy clays referred to the Lafayette (?) formation. Sands 
belonging to the Alum Bluff formation are present on the west side 
of the Chipola River in the southern part of the county, though the 
area where they are exposed is small. 

In a large part of the county the Chattahoochee formation underlies 
the red and yellow sands and sandy clays, but locally these rocks 
are wanting, and the surficial deposits rest on the Vicksburgian lime- 



328 GEOLOGY AND GEOUND WATEKS OF FLOKIDA. 

stones. This is the case near the northern boundary of the county 

in the valleys of all the large streams. The Vicksburgian limestones 

.also lie near the surface in the vicinity of Cottondale and Kynesville. 

The red and yellow sands and sandy clays referred to the Lafa- 
yette ( ?) formation in few places attain a thickness of over 30 feet, 
though locally they may amount to over 50 feet. The sands of the 
Alum Bluff formation are approximately 30 to 35 feet thick near the 
southern edge of the county, but farther north they are entirely 
wanting. The Chattahoochee formation may attain a thickness of 
over 100 feet near the southern edge of the county, but it thins toward 
the north. There is considerable uncertainty concerning the thick- 
ness of the Vicksburgian limestones; but it amounts to at least 
250 feet. 

Mr. John Johnson's well near Yon shows the general character of 
the rocks in the south-central part of the county. After penetrating 
40 feet of red sandy clay (Lafayette ( ?) formation) it enters a white 
marly limestone with some chert beds (Chattahoochee formation) 
and remains in it to the bottom at 150 feet. A good supply of water 
was encountered in a 4-foot channel at 128 feet. A channel 3 J feet 
in diameter was penetrated at 138 feet, and a third of unknown size 
was reached at 146 feet. 

WATER SUPPLY. 

Source. — All the geologic formations represented in Jackson County 
contain more or less water. The surficial sands and sandy clays 
yield an abundant supply for shallow wells and are regarded as 
excellent aquifers. Near the southern boundary the sands of the 
Alum Bluff formation furnish water for a few shallow wells, but 
their areal distribution is small and they are relatively unimportant. 
The limestones of the Chattahoochee formation are important water- 
bearing rocks, but the water occurs in underground channels irregu- 
larly distributed ; hence it is sometimes difficult to find large supplies, 
and many wells are sunk to the underlying Vicksburgian limestones. 
The latter are the most important water rocks in the county, and 
wells which penetrate them have never failed to obtain large quanti- 
ties of water. 

Quality. — The water in the surficial sands and the sands of the 
Alum Bluff formation is soft. Both the Chattahoochee formation 
and the Vicksburgian limestones ordinarily yield hard water, but the 
water from a few wells penetrating these formations is reported to 
be soft. 

Development. — Shallow wells usually obtain ample supplies at 
depths ranging from 20 to 40 feet; some, however, obtain abun- 
dance within a few feet of the surface and others have to go down to 
60 feet. Most of the drilled wells are 100 to 200 feet deep, though 















Head 
above 

or 
below 
surface. 


Depth 

to 
rock. 


Depth 

to 
princi- 
pal 
supply. 


Quality of water. 


Depth 

second ' Remarks, 
supply. 


Feet. 
—19 


Feet. 


Feet. 


Hard.. . 


Feet. 


Forms scale la boilers. 


-35 





275 


.. .do.... 




do 




-50 
-30 
-15 


■■■Iq- 


315 
100 


. .do... 


265 
60+ 




do 




.do... 














-30 
42 


"52" 


110 
75 


Hard 


40+ 




do 


Yields 50 gallons per minute. 


...do 














Drill lost and well abandoned. 


—10 


40± 




Hard 














+6 


219 
60 


262 
219 

90 
45 


Hard. ... 




Yields 50 gallons per minute. 


—32 


Soft 


50 


Yield large. 


39 


Soft? 




do.? 

do.? 


f 45- 
i 65- 


} 


23 


32 


Yields 10 gallons per minute. 












Well abandoned when drill was lost. 


-90 

-50 
-55 




232 

140 
180-190 


Hard 


100 

40+ 
38+ 




do 




do 




















-45 
—36 


65 

60 


150 

40 


Soft and slightly 

alkaline. 
Soft 


125 













U. S. Geol. Survey No. 102, p. 246. 



Typical veils of JncJcRon County. 




Frank Reddick 

Z. T. Stallings 

F. J. White & Co.... 

J. E. Goodwin 

McNiel tfe Jolinson., 
J. R. Showmaker... 
Little, White & Co.. 
W.H.Logan 

Dr. J. E. McCleod . , 

R.L.Norton 



E. B. Bradley.... 

B. L. Porter 

W. J. Singletary. 



F. J. White & Co.. 
iiudiey 



Bradley & Have 



Land & Vanfleet. 



Chattahoochee forma- 
Vicksburgian lirae- 
ChattahOQChee forma- 



Chattaboochee forma- 




Domestic and druiking 
Domestic and 



Turpentine still.. 



Icefacl^ry 

Domestic and si 
I'ubuc supply.. 




: Water-Supply Paper U. 



[■ 319—13. (Ta face page 32S.) 



JACKSON COUNTY. 



329 



some find good water within less than 100 feet of the surface, and 
several exceed 200 feet. The public well at Campbellton is 315 feet 
deep, and the city supply at Marianna is obtained from a well 386 
feet deep. The only flowing well in the county is at Graceville, 
where water of excellent quality has sufficient head to rise about 6 feet 
above the surface. It is possible that other flowing wells might be 
obtained in some of the stream valleys, but the conditions are too 
imcertain to permit safe predictions. 

There are three public water supplies in Jackson County, all obtain- 
ing water from drilled wells which penetrate the Vicksburgian lime- 
stones. The largest system is at Marianna and is owned by the 
Marianna Water Co. The water is hard but of fair quality and is 
ample in quantity. Many of the inhabitants, however, prefer to use 
water from private wells, and the average daily consumption from 
the city supply is small. The Aycock Lumber Co. has a well which 
supplies its lumber camp, to which the water is distributed through 
mains. The State Reform School has its own supply, obtained from 
a well on the premises; the quantity is ample and the quality 
satisfactory. 

General water resources of Jackson County. 





Topographic 
location. 


Source of 
water. 


Surface 
formation. 


Shallow wells. 


Town. 


Depth. 


Supply. 


Quality of 
water. 


Principal 
water bed. 




Plain 


Dug and driven 
wells. 

do 


Pleisto- 
cene sand 
and La- 
.fayette(?) 
...do 


Feet. 
18-20 

7-45 
20-60 

40-50 
20-60 

20-40 

20-40 
50-80 

35-60 
20-60 


Ample.. 

...do 

Good.... 

...do 

Moderate 

Good.... 

Ample.. 
...do 

Good 

Ample. . 


Soft ^ 

Hard 

...do 

...do 

Soft 

Hard 

Soft 

...do 

Hard 

Some soft, 
mostly 
hard. 




Bonifay 

C a mpbell- 

ton. 
Cottondale. 
Cypress 

Graceville. 


Hilly 


limestone. 
Do. 


Rolling . . 


do 


Pleisto- 
cene sand. 

...do 

...do 

...do 

...do 


Do 


ao 

Gently rolling . 
Plain 


do 

Dug and bored 

wells. 
Dug and drilled 

wells. 
do 


Do. 
Do. 

Do. 


Grand Rdg. 
Greenwood 

Mariarma 


Gently rolling. 
do 

HiUy 


Do. 


Dug and one 
drilled well. 

Dug and drilled 
wells; public 
supply. 

Dug and drilled 
wells. 


...do 

Pleisto- 
cene and 
L a f a- 
yette(?). 

P 1 e i s to- 
cene. 


Do. 
Do. 


Sneads 


Gently rolling. 


Do. 



330 GEOLOGY AND GKOUND WATEKS OF FLOKIDA. 

General water resources of Jackson County — Continued. 





Deep wells. 


Average 
thick- 
ness of 
sand. 


Depth to 
water. 


Increase or de- 
crease of supply. 




Town. 


Depth. 


Supply. 


Head 

above 

sea. 


Quality 

of 
water. 


Sewerage 
system. 


Alliance 


Feet. 




Feet. 




Feet. 


Feet. 
15 
5-30 
10+ 

8-20 
Varies. 

10± 
30 ± 
50 ± 
20-30 
60+ 


None 




Bonifay 

C a mpbell- 

ton. 
Cottondale. 


398i 
815 

80-135 
60-300 

262i 
90-150 


Good 




Hard.... 
...do.... 


45+ 
Thin. 

Thin. 
40± 

Thin. 

30+ 

10-30 

20+ 

50± 


do.... 


Do 






Slight 


Do. 


...do 




.. do.... 


do 


Do. 


Cypress 


do.... 




do 


Varies with rain- 
fall. 
Slight 


Do. 


...do 

Good... 


6+ 


...do 

.. do.... 


Do. 


Grand Rdg. 
Greenwood 


Due to weather.. 


Do. 








Do. 




386 
100-200 






Hard.... 
...do 


Slight 


Do. 


Sneads 


...do 




Due to weather.. 


Do. 













JEFFERSON COUNTY. 

By G. 0. Matson. 
GENERAL FEATURES. 

Jefferson County occupies a comparatively narrow area in north- 
ern Florida, extending from the Georgia line southward to the 
Gulf of Mexico. Its surface varies from a low plain rising only a 
few feet above sea level to rolling uplands with an altitude of over 
200 feetj the southern end being a low sandy terrace 20 to 30 feet 
above tide. Farther inland there is a second terrace of 40 to 60 feet 
in altitude and a third with an altitude of 70 to 100 feet. The lower 
terrace in the southern part of the county contains many swamps, 
and the upper terraces, though in few places swampy, have some 
lakes. The largest — Lake Miccosukee — appears to occupy a depres- 
sion in the limestone which underlies the second terrace; it drains 
southward to a sink hole communicating with an underground 
stream. St. Marks and Aucilla rivers receive a large part of the 
drainage of the county, though in the southern part some small 
streams flow directly to the Gulf. 

GEOLOGY. 

On the terraces the Pleistocene gray sands form the surface de- 
posits, and in the northern part of the county the surface is formed 
by residual sands underlain by red and yellow sands and sandy clays 
referred to the Lafayette ( ?) formation. The sands and clays of the 
Alum Bluff formation may underlie the Lafayette ( ?) formation in 
some of the upland near the northern boundary of the county, but 
their presence is not easily determined. The entire county is under- 
lain at no great depth by the Chattahoochee formation, but this 
formation is seldom seen except in the depressions where the over- 



JEFFERSON COUNTY. 331 

Ijmg formations have been removed by erosion. Beneath the 
Chattahoochee are the Vicksburgian limestones, but these rocks are 
too deeply buried to be exposed. 

In the southern part of the county the gray sands of Pleistocene 
age may reach a maximum thickness of over 50 feet. The thick- 
ness of the Lafayette ( ?) formation averages less than 30 feet and 
the maximum probably does not exceed 50 feet. The Alum Bluff 
formation if present is comparatively thin, but the Chattahoochee 
formation may amount to over 100 feet. The Vicksburgian lime- 
stones are doubtless several hundred feet thick. 

WATER SUPPLY. 

Source. — Water in Jefferson County is chiefly obtained from the 
surficial sands, which furnish an abundant supply within a few feet 
of the surface and are extensively drawn upon throughout the 
county. Deeper supplies are obtained from the Chattahoochee for- 
mation and the Vicksburgian limestones. The quantity of water 
obtained from these formations is very large, but the head of that 
in the Vicksburgian limestones is not great enough to bring it to the 
surface on the upland near the northern edge of the county. 

Quality. — The surficial sands usually furnish soft water. The 
water from the limestones of the Chattahoochee formation is moder- 
ately hard but is satisfactory. The Vicksburgian limestones also 
furnish hard water free from sulphur near the northern end of the 
county, though farther south sulphur water will probably be obtained 
in deep wells penetrating these limestones. 

Development. — Shallow wells form the principal means of water 
supply throughout a large part of Jefferson County. They com- 
monly range from 15 to 30 feet in depth, though a few are as much 
as 60 feet deep. The water is suitable for all domestic and industrial 
uses, and the water level is near enough to the surface to make 
pumping easy. Where such wells are used care should be taken to 
locate them far enough from buildings and other sources of pollu- 
tion to avoid danger of contaminated surface water mingling with 
the supply of the well. 

Only three deep wells are reported from Jefferson County, two of 
them located at Monticello and one at Lamont. The deepest weU 
in the county, the 800-foot well at MonticeUo, is used for a public 
water supply; it may be supplemented by a second well 400 feet in 
depth that is held in reserve in case the first well should not furnish 
enough water. These wells probably penetrate the Vicksburgian 
limestones ; they furnish moderately hard water, but the supply is 
regarded as satisfactory for domestic and industrial purposes. The 
quantity is ample to meet aU the needs of the town and the water 



332 GEOLOGY AND GKOUND WATERS OF FLORIDA. 

system is good. The well at Lamont is only 132J feet deep and 
probably obtains its supply from the Chattahoochee formation. The 
water is hard but is regarded as very satisfactory. At Monticello 
the head of the water from the Vicksburgian limestone is sufficient 
to bring it within about 150 feet of the surface. It is possible that 
flowing wells might be obtained in the extreme southern end of the 
county, where the surface is low, but it would be necessary to drill to 
a depth of 350 to 450 feet. 

Jefferson County contains a number of small springs and some of 
considerable size. The most important are Walker Spring, 8 miles 
south of Lamont; Cassidy Spring, 1 J miles south of Wacissa; and Big 
Blue SpriQg, 2 miles south of Thomas City. The water from Walker 
Spring is used for drinking and is reported to be hard and to con- 
tain some sulphur. The other springs mentioned also supply hard 
sulphur water, but they are not used. 



JEFFEESON COUKTY. 



333 





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334 



GEOLOGY AND GROUND WATERS OF FLORIDA. 



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GEOLOGY AND GEOUND WATEES OF FLOEIDA. 335 

LAFAYETTE COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Lafayette County borders the GuK coast near tlie northern end 
of the peninsula, extending over 50 miles northward between Suwannee 
and Steinhatchee rivers. Its surface is made up of broad terraces, 
the lowest rising only a few feet above sea level, the altitude increas- 
ing gradually back from the coast. A second terrace begins several 
miles inland and extends for a long distance and is succeeded by 
a still higher terrace. More than one-half the surface lies between 
50 and 100 feet above sea level and a considerable area is less than 
25 feet. Swamps occupy a large area near the northern end of the 
county and extend southward and southeastward a distance of over 
30 miles. Near the eastern border there are many lakes of moderate 
size. 

GEOLOGY. 

The Pleistocene terraces of Lafayette County are covered by gray 
sand underlain by older sands and marls. Beneath the surficial 
sands lie the sands and clays of the Alum Bluff formation and the 
limestones of the Hawthorn formation; near the southeastern corner 
of the county the Vicksburgian limestones are believed to be near 
the surface. 

In the absence of satisfactory well samples, it has been practically 
impossible to obtain information concerning the thickness of the sub- 
surface materials of Lafayette County. To judge from conditions in 
adjoining counties, the surficial sands may attain a thickness of more 
than 50 feet and the Alum Bluff and Hawthorn formations probably 
200 feet. There is no question that the Vicksburgian limestones, 
which underlie the county, have a thickness of several hundred feet. 

WATER SUPPLY. 

Source. — The surface sands form an excellent source of water sup- 
ply in Lafayette County, and doubtless many of the weUs obtain 
water from the Alum Bluff and the Hawthorn formations. The 
Vicksburgian limestones are the best water-bearing beds of the county, 
but as yet the water from them has not been extensively developed. 

Quality. — The sands supply soft water. Hard water, which may 
contain sulphur in some localities, is to be expected from the Haw- 
thorn formation. The Vicksburgian limestones will doubtless supply 
hard sulphur water and in some localities salt water. 

Development. — Few of the shallow wells of Lafayette County 
exceed 30 feet in depth, and they obtain an abundance of soft water 
76854°— wsp 319—13 ^22 



336 



GEOLOGY AND GKOUND WATERS OF FLOEIDA. 



which is utihzed for domestic and farm supplies. Near the northern 
end of the county several wells have been sunk to a depth of 50 to 90 
feet and a few exceed 100 feet. These wells obtain large quantities 
of hard water, which rises within 20 to 40 feet of the surface. The 
water level in the shallow wells is sufficiently near the surface to 
permit it to be raised by means of suction pumps, but in the deep 
wells it is necessary to use some kind of a deep-well pump. Mayo 
is the only town in the county having a public water supply. The 
water is obtained from a flowing well 120 feet deep, and the supply is 
ample for the present needs of the town. A wooden tank has been 
built, from which distribution is made by gravity. 



LAFAYETTE COUNTY. 



337 






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338 GEOLOGY AND GKOUND WATEKS OF ELOKIDA. 

IjAke county. 

By G. C. Matson. 
GENERAL FEATURES. 

Lake County, in the north-central portion of the peninsula, occupies 
a part of the lake region and extends eastward to St. Johns Kiver. 
A narrow belt along St. Johns River lies 20 to 30 feet above the 
stream and forms a well-defined terrace separated from the higher 
land to the west by an abrupt scarp. Another terrace has an altitude 
of 40 to 60 feet, and a third, more poorly defined, rises to 70 to 100 
feet. In the north-central and southeastern portions of the county 
the upland has an altitude of over 100 feet. 

The surface of the county is dotted with lakes and, near the south- 
west corner, with extensive swamps. Many small lakes occupy 
sinks in the limestones, and some of the larger ones are in broad 
depressions which may be largely due to solution. Large streams 
are generally absent within the county, a condition apparently due 
to the existence of extensive underground drainage systems. 

GEOLOGY. 

The surface formation of Lake County is of gray sand, underlain 
by gray, yellow, brown, and pink sands, locally more or less clayey, 
which are the weathered products of the underlying rocks. Near 
St. Johns River Pleistocene sands rest on the shell marl of Pliocene 
age (Nashua marl). The exact distribution of the Nashua marl has 
not been determined, but the formation may extend some distance 
west of the river and may also underlie the swampy uplands at the 
extreme southern end of the county. The Miocene shell marl (Choc- 
tawhatchee marl) has not been found in Lake County, but that it 
probably underlies the areas covered by the Nashua marl is inferred 
from the fact that it occurs to the eastward in St. Johns Valley and 
to the southward at Kissimmee. The Alum Bluff formation is repre- 
sented by sands and clays and fullers' earth resting on the Hawthorn 
formation. The Hawthorn formation consists of sands and locally 
of clays and impure limestones. The sands are remarkable for their 
beautiful coloring, ranging from gray through various shades of pink, 
buff, yellow, and brown; the colors are doubtless due to the action 
of the weather on the impurities of the original rock. Beneath the 
Hawthorn formation lie the porous gray to white Vicksburgian lime- 
stones. They consist of alternating beds of soft and hard rock with 
some layers of chert and some black grains, which are probably 
phosphate. 

The thickness of the Pleistocene sands in few places exceeds 30 
feet, and the PHocene marls probably average less than 25 feet. 
The sands and clays of the Alum Bluff formation are over 100 feet 



LAKE COUNTY. 



339 



thick, and the Hawthorn formation has a thickness of nearly 100 
feet at some localities but is much thinner in the valleys where it 
has been partly removed by erosion. The Vicksbtirgian lime- 
stones are known to have a thickness of several hundred feet in the 
peninsula generally, but no direct information concerning their thick- 
ness could be obtained in Lake County because drilling there has 
always stopped as soon as porous water beds were encountered. 

Some idea of the thickness and character of several of the forma- 
tions in Lake County may be gathered from the well logs given 

below: 

Partial log of the well of Charles G. Megargie, at Eustis. 

Feet. 

Sand, coarse grained, brown 3- 30 

Sand, coarse grained, gray 80- 90 

Limestone, soft, light gray. 146-154 

Limestone, hard, light gray; with shell fragments characteristic 

of the Ocala limestone 154-163 

The well whose record follows is about 200 yards north of the 
C. G. Megargie well above. 

Log of J. J. Harrison^ s well at Eustis. 



Thickness. 


Depth. 


Feet. 


Feet. 


3 


3 


9 


12 


8 


20 


4 


24 


18 


42 


5 


47 


8 


55 


8 


63 


]2 


75 


2 


77 


12 


89 


1 


90 


5 


95 


2 


97 


3 


100 


12 


112 


2 


114 


2 


124 


i 


124i 


2i 


127 


3 


130 


1 


131 


6 


137 


7 


144 


15 


159 


1 


160 


12 


172 


2 


174 



No samples 

Sand, medium grained, yellow 

Sand, similar but lighter colored 

Sand, medium grained, light buff 

Sand, white, fine and coarse grained, mixed 

Sand, white, containing a little gravel 

Sand, white to brownish 

Sand , light buff 

Sand , pink ' 

Sand, pale yellow 

Sand, bluish; with clay 

Sand, gray 

Sand, brown; with clay 

Clay, dark colored, and sand ; many fragments of sheUs 

Marl, dark colored, greenish 

Limestone, soft, light colored; with dark phosphatic grains 

Limestone, light colored, marly; with dark phosphatic grains 

Limestone, light colored; many phosphatic grains 

Limestone, light colored, porous; with fragments of shells, grains of sand, and dark 

phosphatic nodules. 

Limestone, light colored, marly; with black phosphatic nodules 

Clay, light colored; with black phosphatic grains 

Similar to last but containing some lime 

Limestone, soft, brown; with shell fragments 

Limestone, dark colored; with chert and sand 

Limestone, light colored; with dark grains and some light-colored chert 

Limestone, brown 

Limestone, hard, light gray 

Limestone, soft, dark gray 



The first water was found at 45 feet and other supplies at inter- 
vals to 77 feet. It rose 15 feet above the point where it was first 
encountered. There was a slight additional supply between 89 and 
90 feet, and another at 124 feet. The principal supply was reached 
at 174 feet and the water rose within 41 feet of the surface. All 
the water in this well is reported to be soft. The Vicksburgian 
limestones were probably encountered at a depth of about 131 feet. 



340 GEOLOGY AND GROUND WATEES OF FLOEIDA. 

Log of Malone Sweet's well at Eustis. 



Tthickness. 



Depth. 



Sand, dark 

Sand, yellow 

Sand, light yellow 

Sand, fine grained, yellow; containing pebbles 

Sand, fine grained, yellow 

Sand, white, and pebbles , 



Feet. 





Feet. 


1 


1 


2 


3 


21 


24 


16 


40 


1 


41 


^ 


44. 



Water was encountered between 32 and 40 and between 41 and 
44^ feet. The first supply rose 10 feet in the well and the second 



14i 



feet. The yield is small. 



Log of well of S. M. Weld at Mount Dora. 



Thickness. 


Depth. 


Feet. 


Feet. 


1 


1 


9 


10 


8 


18 


4 


22 


10 


32 


10 


42 


13 


55 


9 


64 


9 


73 


12 


85 


7 


92 


5 


97 


10 


107 


18 


125 


18 


143 


37 


180 


1 


181 



No samples 

Sand, medium'grained, buff 

Sand, slightly finer, light buff 

Sand, mixed fine and coarse grained, light buff. . 

Sand, fine grained, light brown 

Sand, fine grained, pmk; a little clay 

Sand, fine, yellow; a little clay 

Sand, fine grained, bufl 

Clay, bufl, sandy 

Limestone, light yellow, sandy 

Limestone, bufl, sandy 

Sandstone, soft; containing lime and clay (marl) 

Marl, drab, sandy 

Limestone, light brown, sandy 

Sandstone, light brown to gray; containing lime. 

Limestone, light gray 

Limestone, gray; fragments of shells 



The Vicksburgian limestones probably lie between 107 and 125 feet. 

Log of well of Mr. Blake at Grand Island. 



No record 

Sand, yellow 

Sand, very fine, pink 

Sand, very fine, pale pink 

Sand, coarse gramed, gray; particles of lime 

Sand, very fine grained, gray 

Lime clay, greenish 




LAKE COUNTY. 341 

Log of well of the Florida Fertilizer Co. at Grand Island. 
[From samples in possession of the U. S. Geological Survey.] 



Thickness. 


Depth. 


Feet. 


Feel. 


4 


4 


15 


19 


12 


31 


39 


70 


14 


84 


8 


92 


10 


103 


13 


116 


7 


123 


4 


127 


3 


130 


8 


138 


5 


143 


11 


164 


6 


170 


13 


183 



No samples 

Sand, coarse, bufE 

Sand, coarse, light yellowish gray 

Sand, coarse and fine, light gray 

Sand, fine, pink 

Sand , medium, pink 

Sand, coarse, reddish brown 

Sand, light gray, partly indurated; some lime 

Clay, greenish gray, sandy 

Limestone, hard, light gray; black grains of phosphate. 

Limestone, greenish gray, marly 

Limestone, light gray, granular 

Limestone, hard, light gray 

Limestone, white, granular 

Limestone, soft, light gray 

Limestone, hard, light gray 

Limestone, gray, porous 



Water was reported at 100 feet, and the principal supply was 
encountered at 183 feet. 

WATER SUPPLY. 

Source. — Neither the Pleistocene gray sands nor the Pliocene 
shell marls are important water-bearing formations, though they 
may furnish some water for shallow weUs. The Alum Bluff and 
Hawthorn formations furnish considerable water at moderate 
depths, but the principal source of supply is the Vicksburgian lime- 
stones. These rocks underlie the entire county and are generally 
reached by wells at moderate depths. 

Quality. — ^The shallow wells of Lake County obtain soft water, 
but the deep wells, especially those entering the Vicksburgian lime- 
stones, get only hard. Some of the water from the Vicksburgian 
limestones contains hydrogen sulphide. The water from the large 
springs is moderately hard. 

Development. — In Lake County good supplies of soft water are 
obtained by weUs ranging in depth from 10 to 50 feet, the common depth 
being less than 30 feet. The Hawthorn formation supplies some 
water within 100 feet of the surface, but most wells are sunk to a 
somewhat greater depth. Many of them enter the Vicksburgian 
limestones, where they obtain large supplies of hard water, much of 
which contains more or less sulphur. 

Deep weUs encounter large supplies of hard water between 75 and 
300 feet. Sulphur occurs in the water of many of the deeper wells, 
and some of them obtain two or more supplies of different mineral 
characters; the shallow supplies may be soft and the deeper waters 
hard or sulphur bearing. Such weUs yield water which is a com- 
posite of all the supplies encountered, unless casings are inserted to 
exclude some of them. 



842 GEOLOGY AND GEOUKD WATERS OF FLORIDA. 

Flowing wells may be obtained on the low terrace which borders 
St. Johns River, and should flow freely to a height of at least 20 feet 
above the river. The amount of water supplied by these wells will 
vary with local conditions but should usually be large. The quality 
of the supply is indicated by the well at Astor, which yields hard 
sulphur water. Flows occur sporadically in the lake region, but they 
depend on local conditions and there is no possibility of teUing where 
they may be obtained. 

Leesburg has the only public water supply in Lake County. The 
system is owned by a private company and is well equipped. The 
water, which is taken from three wells, 98, 100, and 101 feet deep, 
is hard but is reported to be satisfactory and ample in quantity. 

Springs are numerous in Lake County, but none of them are exten- 
sively used. Two of the most important are the Big Spring near 
Okahumpka and the Seminole Spring near Sorrento. Both yield 
hard sulphur water and flow good-sized streams. The estimated 
flow of the Big Spring is 15,000 gallons per minute, and that of the 
Seminole Spring is 25,000 gaUons. These springs might serve as 
centers for resorts if hotels and bathhouses were constructed near 
them. 

















Nearest town or 
post office. 


Directio 
distan 


h 


Depth 

princi- 
pal 
supply. 


Pro- 
tecting 
clays 
present. 


Quality of water. 


Remarks. 




Near 

i mile soul 
Near 


Feet. 




Hard, sulphur 

do 






















Second supply at 54 


Do 


-■ 


170 
124 

186 
40 


Yes 


Soft 


feet. 


Fruitland I'ark 

Grand Island 


i mile sou* 
Near 

1 mile east 

Near 

2 miles we 

1 mile sout 
do 




Sulphur 






Soft 




Sulphur 






Hard 




Do 


-- 


175 
95 


Yes... 
Yes... 
Yes... 


do 

do 

do 

do 


Second supply at 125 


Do 


feet. 


Do 




Mount Dora 

Okahumpka 


i mile nor 

Near 

Smiles... 

n miles so 

Near 

1 mile east 
i mile wes 


^5 

-- 


180 
110 


, 


Yes... 


do 








Starts in Pleistocene. 








Yes... 
Yes'!! 


Hard 


Water from Vicks- 
burgian limestones. 




■• 


115 
124 
243 


Sulphur 






Soft 






Hard 










76854° 


-wsp 319— 










' 



Typical wells of TMte County. 





Diroction aiKl 


Owne. 


Driller. 


Date 


^'S.^' 


use. 


Depth, 


Diam- 


Casing. 




Head- 


r 


Depth 
prinei- 
supply 


tX 

Clays 
present 


Quality of walcr. 




Nearest town or 
postofflco. 


4r 


Above 
sea. 


Above 


Kemarks. 




Near 

J^mile southeast... 


A. .\. Thompsou 


S.H. Hoagland 


1905 


.'^S'."':- 




Fed. 
82 

74 

1-3 

ISO 

550 
175 
98 
101 
110 

lOi 
US 

243 


Inches. 
I 


Feel. 
125 


Feel. 
15 


Feel. 
29 


Feel. 
+14 

-3 

-62 


Feet. 


Feel. 




Hard, sulphur.... 
































Second supply at 54 




i mile southwest.. 


Dibhlo & Earnest 1... 




1907 


...do.... 




58 

jf 

2 

6- 
6 

2 


■■■:," 








"" 


Yes... 










200 










t'loriclo Fertilizer Co.. 


Dibble .4 Earnest 


1900 


Drilled.. 










imileeast 








-10 
-20 
-20 
-27 









I/H!sbiire 




p 


(1880 

1S92 
1905 

1907 


■Drilled.. 

...do 

...do 

...do 

::t::::: 

...do 

...do 


rublic 








„ . 






2 miles west 

do 




' ^ 


Irrigation 

Ice manufacturing, 

city supply. 
Emersenoy supply... 


84 
95 
95 
110 








95 


Yes... 
Yes... 
Yes... 
'Yes.':; 


do 

do 

:::::do;;::;:::::::: 


Second supply at 125 


Do 


Leesburg leo Co 


do 

A. S. Hardman 

Dibble & Earnest 


87 
- 87 


67 
67 






Mount Dora 


85 


180 
110 




Okahumpka 




Hotel 


99 


72 








Harold Simson 


Domestic and stock... 






IJ miles southeast. 




67 




;'§ 






Yes... 




Water from vS: 
btirglan limestones. 


St. Francis 












115 


243 








fmileeast 

1 mile west 






1906 


Drnled.. 
...do 




124 
240 


66 








Whitney 






'' 




-u 










" 















> Water-Supply Paper U. S. Qeol. Survey No. ; 



LAKE COUNTY. 



343 



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344 GEOLOGY AND GKOUND WATEKS OF ELOKIDA. 

LEE COUNTY. 

By Samuel Sanfoej). 
GENERAL FEATURES. 

Much the greater part of Lee County lies in a region of pine islands, 
cypress strands, and open prairies, and is sparsely inhabited. Only 
a small portion of it is within the Everglades, but the total 
extent of cypress swamp is very large, both the Okaloocoochee Slough 
and the Big Cypress lying withia the county. Mangrove swamps 
fringe the coast from Chokoloskee to Gordon Pass. To the north is 
a coastal belt of sandy pineland that widens rapidly north of Estero, 
and is over 40 miles wide along the north line of the countyo In 
San Carlos Bay and about Pine Sound and Charlotte Harbor are 
many islands, some sandy and comprising little swamps flooded at 
high tides. The settlements, of which the city of Fort Myers is the 
most important, are situated almost wholly along the coast or along 
Caloosahatchee River. The average elevation of the surface is low, 
less than 20 feet; elevations over 50 feet are limited to dunes. Several 
short rivers emptying into passages back of the Ten Thousand Islands 
head in the prairies or cypress swamps; Caloosahatchee Eiver, which 
rises in Lake Hicpochee and empties into San Carlos Bay, traverses 
the north side of the county. 

GEOLOGY. 

Except for the outcrops of Pliocene beds along Caloosahatchee 
River, the known surface formations of Lee County are of Recent or 
Pleistocene age, comprising peat, sands, marls, and limestone. The 
Lostmans River limestone, here and there grading into sand or marl, 
underlies much of the region between the coast and the Everglades. 
Nothing is known of the southward extent of the Pliocene beds 
(Caloosahatchee marl) in the county. The thickness of the Miocene 
sands and marls can not be determined from the evidence available, 
nor have samples enough been saved from deep borings to permit 
definite statements regarding the thickness of the Apalachicola group 
or the depth to the Vicksburgian limestone. The anticlinal structure 
shown to the north extends across the county, the axis of the fold 
being near the coast. The eastward slope of the top of the Vicks-« 
burgian limestone is apparently about 5 to 8 feet to the mile. There 
has been a little late folding — as shown by the gentle flexures of the 
Pliocene and Pleistocene outcrops on Caloosahatchee River (p. 136). 

WATER SUPPLY. 

Source and quality. — Shallow weUs find water in the Pliocene sandy 
marls outcropping on Caloosahatchee River, in the Pleistocene lime- 
stones, sands, and sandy marls, and in the sands of the coastal islands 



LEE COUNTY. 345 

some of which may be classified as Eecent. The water varies in 
character but in general is hard. As it lies near the surface it is cheaply 
developed. 

The Miocene marls and sands and the upper Oligocene marls and 
limestones yield flows in places, notably about Fort Myers and the 
mouth of Caloosahatchee Kiver. The flows are not so copious as 
those from the Vicksburgian limestone, but the waters have much 
the same character, being hard and sulphur bearing. The chlorine 
content is highest in wells on coastal islands. In the eastern part of 
the county the Miocene and upper Oligocene formations are of less 
importance as water bearers; wells in the cattle ranges west of the 
Everglades did not get flows from them. 

The chief source of flowiug water in the county is the Vicksburgiaji 
limestone, which at the north side of the county lies 300 feet below 
the surface along the extension of the anticlinal fold of west-central 
Florida, but which dips to the east and to the west and may be 
1,000 feet below the surface in the southeast corner of the county. 
Depths to flows differ greatly within short distances, owing to the 
erratic distribution of water-bearing porous beds or open crevices. 
(See p. 248.) These flows are often copious, averaging over 100 
gallons per minute from a 3-inch well at ground level, and the heads 
are fairly high, averaging fully 25 feet above tide. The waters vary 
somewhat in mineral content, but all are hard and sulphur bearing. 
A few wells, particularly those on coastal islands, yield water too 
salt for domestic use, and many wells show an increase in chlorine 
content with depth. 

Springs from the Pleistocene sands and limestones are found 
in places but are small and of no special interest or economic 
importance. 

Development. — Shallow dug or driven wells are the chief sources 
of domestic supply. Few of them are over 25 feet deep and the 
average depth is 5 to 20 feet. The driven wells, as throughout 
southern Florida, are mostly equipped with pitcher pumps and cost 
but little to complete. 

Most of the deep drilled wells are 3 inches in diameter. Their 
cost differs because of differences in the character of the beds pene- 
trated. A driller may sink over 300 feet in a week and then spend 
an equal length of time in penetrating a flinty stratum a few feet 
thick. Most wells are cased to the Vicksburgian limestones, where 
the water is obtained from these; and to the water bed if drawing on 
Miocene or upper Oligocene sands and marls. 

Depths vary greatly owing to the erratic distribution of water- 
bearing crevices or porous layers, and the anticlinal structure. Flows 
from the Vicksburgian limestone have been obtained at from 300 to 
over 900 feet. The total number of deep wells in the county is 



346 



GEOLOGY AND GROUND WATEES OF FLORIDA. 



unknown. They have been drilled from Marco to the north line of 
the county, and from islands outside of Charlotte Harbor to the 
prairies west of the Everglades, but nearly all are along Caloosahatchee 
Kiver or near its mouth. (See PI. XVII, A, p. 234.) Details of some 
are given m the table. 

The only attempts at deep drilling reported from the southern 
part of the county are at Marco and Everglade. The Everglade well 
showed the following section : 

Record of well ofG. W. Storter, at Everglade. 



Depth. 



Marl, light gray 

Limestone, soft, blue , 

Sand, fine, white or blui&h, siliceous 




Feet. 



The sand is full of salt water. The well is situated in a small area 
of arable land on an island of marl about 2 feet above high tide. A 
hand rig was used, and drilling was abandoned because of the trouble- 
some character of the sand, which flowed freely yet packed firmly in 
the casing. 

The following record of the well at Marco was given from memory 
by the driller, H. Seniff : 

Record of well of W. D. Collier, at Marco. 



Shells (Indian shell mound, in part) 

Quicksand, white 

Shells, oyster, etc 

Rock, porous, spongy; like coquina, but containing no shells; salt water 



Statements regarding the depth reached by this well differ, but it 
evidently reached a porous limestone overlain by marl and sand. 
The driller abandoned work after strikiQg the salt water at the bottom 
and breakuig a drill rod. The owner subsequently ran a 2-inch pipe 
down to the maiQ flow and utilized it for a bathroom supply at his 
residence. The strong flow is decidedly salt, as is shown by the field 
assay on page 260. A well on the slope of the sand dune at Caximbas 
obtains good water at 15 feet. 

The next deep wells reported along the coast to the north are at 

Estero. The record of one well, given from memory by the driller, 

is as follows: 

Record of well of Koreshan Unity, at Estero. 






Thickness. 


Depth. 


Sand like beach sand 


Feet. 

18 

15 

100 

152 


Feet. 
18 




33 


Sand, white 


133 


Limestone 


285 







LEE COUNTY. 347 

The water is hard and sulphur-bearing but not salt and is used for 
various purposes. 

A number of wells have been drilled about San Carlos Bay, off the 
mouth of Caloosahatchee River. Details of most of these are given 
in the table. There are two wells at Punt a Rasa. The following 
record of one of them was given by the driller, H. Seniff : 
Record of well of H. W. Towles, at Punta Rasa. 




Shells 

Sand, white 

Limestone, white, water 

This well is used for watering stock. The water is hard, sulphur- 
bearing, and brackish. The results of a field assay of a sample are 
given in the table on page 260, as are the results of an assay of a sample 
from the 140-foot well at the hotel near by. 

The driller, James Sykes, gave the following record of a well on a 
key near Punta Rasa: 

Record of well at Fish Factory Key, near Punta Rasa. 




Depth. 



Sand 

■Rock 

Clay, blue, and sand 

Rock, hard, dark, water in a cavity . 



Feet. 
106 
111 
278 
280 



There are two deep wells on Sanibel Island. One, near the center 
of the eastern part of the island, is owned by E. R. Bailey and is 420 
feet deep. It is cased for 250 or 300 feet. The flow of 5 gallons a 
minute at 5 feet below sea level is strongly saline and is not utilized. 
A small flow of fresh water was reported at about 200 feet. No record 
was kept of the strata penetrated but, according to the owner, the 
material washed up was chiefly sand. Shallow wells on Sanibel 
Island get good water at 10 feet. 

The other weU, near the west end of the island, was not completed 
early in June, 1908, though several flows had been found, as the 
owners, who had sunk the well for irrigating supplies, wanted more 
water than had been obtained. The driller, D. Towles, gave the 
following record: 

Record of well of Hope & Heller, at Sanibel Island. 



Sand, with oyster and clam shells 

Clay, blue , 

Sand, light; a few oyster and clam shells and a few layers of hard rock 
Limestone, dark and light, hard and soft; with layer of shells 




348 GEOLOGY AND GKOUND WATEKS OF FLOKIDA. 

Small flows of water were found at 180 and 250 feet. At 344 feet 
the total flow from the 4-inch pipe at an elevation of 5 feet above 
mean high tide, was 20 gallons per minute. At 480 feet the total 
flow was 60 gallons. The character of the water is shown by the 
field assay in the table (p. 260). 

The 605-foot well on Buck Key, one-half mUe east of Captiva, was 
sunk to irrigate an orange grove. The record compiled from the 
driller's statement and from samples was given in the discussion of 
the geology of southern Florida (p. 173). A slight flow was struck 
at 260 feet and a stronger one at 300 feet. The water, as shown by 
field assay (p. 260), is the least saHne of any sampled from wells on 
coastal islands in Lee County. 

The following record of a well in the extreme northwest corner 
of the county, on Josephi Island, near the mouth of Charlotte 
Harbor, was given by James Sykes, the driller. 

Record of well on Josephi Island. 



Thickness. 



Depth. 



Sand 

Bock 

Clay, soft, dark, and coarse dark sand 

Rock; containing cavities; water bearing. 



Feet. 


Feet. 


100 


100 


4 


104 


72 


176 


132 


308 



Of the many wells drilled in Fort Myers only a small number are 
listed in the table. Drillers' statements regardiQg formations pene- 
trated do not harmonize, but this is to be expected, as written records 
have not been kept. Clapp compiled the following generalized section 
from data furnished him : 

Generalized section at Fort Myers. 

Feet. 

Sand 40 

Marl, blue 50 

Sand rock, soft, white to brown 2-10 

Quicksand 30 

Shell rock 40 - 80 

Marl, blue, plastic 60 

Limestone, rotten 40 -100 

Limestone, hard, crystalline 18 - 27 

Limestone, soft, porous; "water rock;" some hard, brown 

layers 200 -300 

Rock, soft, white, granular; like com meal 3 - 4 

"Water rock," like first "water rock" t^ - I 

Limestone, soft, granular; strong flow. 





Depth 
epth to 
to princi- 
ock. pal 

supply. 


Quality of water. 


Yield per 
minute. 




Neare 

P03 


Remarks. 




'^eet. Feet. 




Gallons. 








Alva... 










Buckin, 


407 


Hard 


200 
100 

Many. 

Many. 

Many. 
110 
175 

500 
500 
600 
300 
150 
1,000 

160 
500 




Do 






Estero . 


193 

193 

200 

496 496 
527 

540 

540 

453 

{<=) 

150 403 
600 

350+ 

600+ 


Sulphur 




Doh 


do 




Do J 


. . do 




Do. 


Hard 


Second supply at 400+ feet. 


FortM] 
Do, 

Do, 


Sulphur; some salt 

Sulphur; slight salt .. . 
do 


Do. 


do 




Do. 


do 




Do. 


do 




Do. 


Sulphur 




Do. 

Do. 

Do; 


Soft; iron-sulphur 

Sulphur; some salt 

do 




Do" 


560 

918 


do ... 


200 

400 
400 

200 
Many. 
Many. 




Dol 


Brackish 




Do, 


Sulphur 




Do; 
Do; 


C') 

(c) 

700 

490 

500 


Sulphur; some salt 

do 




Do; 


do 




Do; 


do ... 




Doi 


do 




Do; 


Sulphur and salt 

do 


Quicksand to water rock. 


Do, 




Do. 


Do; 






Do. 


Do 




Sulphur and salt 

.do 


Many. 

Several. 
450 

150 
100 
450 
200 

150 


Do. 


Do; 






Do, 




do 




Do, 


500 

490 

450 

400 

i<^) 


do 




Do; 


do 




Do; 
Do; 
Do^ 


Sulphur; some salt 

do 




do 




Do; 






Fort T]- 


300 300 


do 






Marco. , 






Not completed. 


Punta ]• 






6 
2 


Do" 


125 






Do; 






Do- 




Sulphur 







st. Jane 




do 






Do 




Brackish 






Saaibel 




Salt 






Do 




Hard 






Do, 






Many. 




Useppa 




Salt 


Said to be too salt for drinking. 
No salt water below 60 feet. 


Do 




Hard 


1(jO 


Captivs 












c Near bottom. 











Tyjyical wells of Lee County. 



\mml 



West and.. 

1 mile east. 



F.J. Wilson o.... 
W. A. Flowinco. 
Koreshan Unity. 



. E. Heitmau.... 
. A. Hendereon.. 
s. A. Hendley... 



.C. Reynolds.... 
oval Palm Hotfl. 

'. tLTowles'.. '.!".! 



Hope & HeUer. 
TV. H.Towlcs.. 



Lee CountyWcU Drill 



Lee County Well Drill- 



Lee CountyWellDrill- 



-1 LeeCounly WciliJri'li- 



P 319-13. (To taoe r 



Leo County Well Drill 

inR Co. 
W. H.Towlcs 



Water-supply Paper U. S. Oeol. Survey No. 102, p. 248. 



Vicksburgian 
Vieksburgian 



Drilled.. 
'.'.io'.'.'.'.. 
Drilled!! 



Domestic and £ 



Domestic a 
Hotel..... 



600+ 
250 

, 300 



Hard.. 
Sulphi'i 



Sulphur; some s:: 
Sulphur; slight s: 



Brackish., 
ulphur.. 



250 



Qulcksond to wolor r 



...do 

Brackish.. 

Hard 

Salt 



Said to be too salt for drinking. 



LEE COUNTY. 



349 



The following record of the deepest well at Fort Myers was given 
by the driller, H. Seniff. 

Record of well of W. E. Towles, at Fort Myers. 



Depth. 




' ' Hardpan," sand with muck 

Quicksand, brownish 

Limestone 

Shells, oyster, etc 

Quicksand, white 

Marl, blue, no shells, no grit 

Limestone, white, in layers 2 feet thick with 6 inches of sand between 

Sand, white _ 

Limestone, hard and soft, brownish; soft layers full of shells 



This well was not completed when the above record was noted, 
June 6, 1908. It was then cased to a little over 500 feet and flowed a 
strong stream from between 680 and 960 feet, chiefly from the latter 
depth. The general character of the hard sulphur water is indicated 
by the field assay in the table on page 260. The deep waters from 
different flows show considerable differences. 

Particulars of some of the wells on Caloosahatchee River above 
Fort Myers are given in the table. No detailed records of these wells 
are at hand. 

Among the most interesting wells in southern Florida are those 
drilled on the eastern side of Lee County in the cattle ranges of the 
prairies in the pinelands west of the Everglades. Though records 
were not kept, the wells are of interest because of their depth and 
the facts reported regarding the geology and underground waters. 
The driller found nothing hard near the surface in any of the wells, but 
went through a great thickness of sands which he called '^quick- 
sands." These were coarse, white to dark, and were full of water but 
did not yield flows. In view of the general character of the Pliocene 
and Miocene beds to the north it seems probable that a considerable 
part of the so-called sand was really marl. Some particulars of these 
wells are briefly summarized below: 

Details of ivells southeast of Fort Myers. 
[In feet.] 



Location (T. S.,Il. E.). 


Depth to 
rock. 


Depth to 
flow. 


Depth of 
well. 


T. 46, R. 33 


825 
680 
600 

718 


921 
691 
600 
720 


921 


T.47,R.31 


691 


T. 47,R. 31 


647 


T. 48, R.31 


720 







The water from ah these wells, thougJi drunk by stock, is said to be 
salty. No analyses have been reported. 



350 GEOLOGY AND GROUND WATEES OF FLORIDA. 

Artesian prospects. — Flows under considerable head can be had from 
the Vicksburgian limestones throughout Lee County. The quality 
of the water deteriorates toward the southeast, as the limestone is 
more and more deeply buried, but usable water can probably be 
obtained anywhere in the western half of the county north of Naples, 
except in scattered areas on off-lying keys. The cattle range wells 
in T. 46 S., E. 33 E., T. 47 S., R. 31 E., and T. 48 S., R. 31 E., indicate 
the quality of the water to be expected along the eastern side of the 
north half of the county, though the quality should be better toward 
the northern boundary. 

Toward the south line of the county the deep water becomes more 
miaeralized, and there is slight chance of getting potable water at 
Chokoluskee and Everglade from deep wells. Shallower wells are not 
likely to furnish fresh water in the keys of the Ten Thousand Islands. 

LEON COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Leon County, in the northern part of Florida, includes a portion 
of the broad upland that extends from east of Monticello westward 
to Pensacola. This upland has been deeply eroded by streams 
and is now gently rolling, with many rounded hills that rise 100 feet 
or more above the adjacent valleys. The city of Tallahassee stands 
on a remnant of this upland and the hill in the central portion of the 
town has an altitude of about 200 feet. 

Broad depressions, which may be in part due to solution, are 
occupied by lakes, the most important of which are Lake Lafayette, 
near Tallahassee, and Lakes Jackson and lamonia, in the northern 
part of the county. There are many similar but smaller lakes and 
some of them are thought to occupy sink holes in the underlying 
limestone. Lake Miccosukee, near the northeast corner of the 
county, occupies a broad depression in limestone of the Chattahoochee 
formation and drains to an underground channel in the same forma- 
tion. In the southern part of the county a broad terrace rises from 
60 to 80 feet above sea level and extends northward beyond Talla- 
hassee. Along Ochlockonee River another terrace ranges in altitude 
from 40 to 60 feet above sea level and has a breadth of about a mile. 

GEOLOGY. 

The terrace formation in Leon County consists of gray Pleistocene 
sand which rests unconformably upon the older deposits. On the 
uplands there are red and yellow sands and sandy clays referred to 
the Lafayette ( ?) formation. This formation underlies the entire 
upland portion of the county and eroded materials from it are 



LEON COUNTY. 351 

frequently found beneath the gray sands of the terraces. Southwest 
of Tallahassee there are numerous exposures of gray shell marl 
(Choctawhatchee marl). This formation may be seen at Black's 
sawmill and at numerous other localities in the vicinity of Holland 
post office. It is also known to extend along Ochlockonee Eiver as far 
south as Bloxham. 

Where the Choctawhatchee marl is absent, the Lafayette ( ?) forma- 
tion rests on blue or gray sands and clays belonging to the Alum 
Bluff formation, which in turn rest on the hard light-colored lime- 
stones of the Chattahoochee formation. 

The Vicksburgian limestones underlie the entire county, but they 
are so deeply buried that their presence can be detected only in the 
drillings from such wells as the one at the city waterworks in Talla- 
hassee. The sands and clays referred to the Lafayette ( ?) formation 
are well exposed in the vicinity of Tallahassee and on the slopes of the 
hills throughout the northern part of the county. The Alum Bluff 
and Chattahoochee formations are seldom seen, but some small expo- 
sures of the formation appear on the hillsides and numerous others 
along Ochlockonee River. 

The gray sands of Pleistocene age are commonly thin, though 
locally they may attain a thickness of over 20 feet. The Lafayette ( ?) 
formation probably averages less than 30 feet in thickness, but it 
may reach a maximum of over 50 feet. The Choctawhatchee marl 
is at least 30 feet thick in the viciaity of Black's sawmill, but toward 
the north it is much thinner, its maximum thickness being probably 
less than 50 feet. In Leon County the thickness of the older geologic 
formations has not been determined, but it is thought that the 
deep wells at Tallahassee pass through the Chattahoochee formation 
and enter the Vicksburgian limestones. 

WATER SUPPLY. 

Source. — All the geologic formations occurring in Leon County 
contain more or less water. Throughout the upland portion of the 
county the red and yellow sands and sandy clays of the Lafayette ( ?) 
formation supply the water for shallow wells. The Choctawhatchee 
marl is not an important aquifer, though it supplies a few shallow 
wells near Ochlockonee River. Good supplies of water should be 
obtained from the sandy beds of the Alum Bluff formation, but it is 
difficult to determine by means of well records whether the water 
comes from these beds or from the overlying Lafayette ( ?) formation. 
Both the Chattahoochee formation and the Vicksburgian limestones 
are excellent sources of water, but the Vicksburgian beds are most 
important because they contaia much larger quantities than the 
76854°— wsp 319—13 23 



352 GEOLOGY AND GROUND WATEKS OF FLORIDA. 

Chattahoochee. However, the limestones of the Chattahoochee 
formation are encountered near the surface and many wells do not 
penetrate to the underlying Vicksburgian rocks. 

Quality. — ^The water obtained from the Lafayette ( ?) formation is 
usually soft, though that from the deeper wells may be moderately 
hard. Both the Choctawhatchee marl and the Alum Bluff formation 
should furnish water containing but small quantities of mineral 
matter. The water from both the Chattahoochee formation and the 
Vicksburgian limestones is hard. 

Development. — ^Most shallow wells obtain good supplies of water 
within 20 or 30 feet below the surface throughout the county. 
For this reason but few deep wells have been drilled except in places 
where large quantities of water are needed for industrial or for city 
supplies. At Chaires the Seaboard Air Line Eailway has a well about 
35 feet deep which obtains an abundance of water from limestone of 
the Chattahoochee formation. The same formation probably supplies 
water for one or two of the deep wells in Tallahassee. The wells of the 
Tallahassee Waterworks Co. probably penetrate the Vicksburgian 
limestones and these rocks are believed to be the sources of the 
principal supply. The water supply for Tallahassee is taken from a 
well 717 feet deep, and the quantity is ample for all purposes. Two 
auxiliary wells, each 400 feet deep, may be drawn upon if the well 
now in use should prove inadequate. 



i 



LEON COUNTY. 



353 



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354 GEOLOGY AND GKOUND WATEKS OF FLORIDA. 

LEVY COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Levy County occupies a large area ou the Gulf Coast of the penin- 
sula and extends eastward to the border of the lake region. The sur- 
face is low and fiat near the coast but becomes more gently rolling 
farther inland. In the eastern half of the county lakes and sink holes 
are interspersed with rounded hills. A large portion of the county 
lies below the 50-foot contour, but near the northeast corner the 
surface is more than 100 feet above sea level, and similar highland 
areas are numerous in the adjoining counties to the east and south. 

GEOLOGY. 

Below the 100-foot contour the county is mantled by gray Pleisto- 
cene sand which is either underlain by the porous Vicksburgian lime- 
stones or by limestones and clays of the Apalachicola group. Near 
Levyville there is an area where the Hawthorn formation is believed 
to be present. The Alum Bluff formation underlies a portioii of the 
county. Some small patches of Alachua clay are known near 
Suwannee Eiver and in the northeastern part of the county. 

The average thickness of the Pleistocene sands is probably not 
more than 20 to 30 feet, though the maximum may be somewhat 
greater than 50 feet. Both the Alachua clay and the Hawthorn for- 
mation are thin, the former being probably less than 15 feet thick 
and the latter in few places exceeding 40 to 50 feet. The thicknesses 
of the Alum Bluff formation and of the Vicksburgian limestones are 
not known, though that of the latter is believed to be several hundred 
feet. 

WATER SUPPLY. d 

Source. — ^The three important sources of water in Levy County are 
the sands of the Alum Bluff formation, the sands of the Pleisto- 
cene, and the Vicksburgian limestones. None of the other formations 
represented in the county are important, though locally they may 
supply water for a few wells. The sands of the Alum Bluff and of 
the Pleistocene are the source of most of the water used for domestic 
purposes and for stock. The Vicksburgian limestones furnish water 
for a number of deeper wells and are especially important as a source 
of supply for industrial purposes. 

Quality. — ^The Pleistocene sands yield soft water which is generally 
regarded as excellent. The Vicksburgian limestones yield hard water. 
Near Cedar Key brackish and salt waters have been encountered in 
the limestones; but the wells there were sunk to a depth of over 800 
feet and may have been heedlessly drilled past beds which would 
supply fresh water. 



LEVY COUNTY. 355 

Development. — ^The shallow wells of Levy County range in depth 
from 10 to 40 feet. They supply nearly all the water that is used in the 
county and are generally satisfactory, though for domestic use the 
hard water from the deeper wells is probably more desirable. Drilled 
and driven wells range in depth from about 40 to 865 feet, but the 
most of them are less than 100 feet. These wells yield hard water 
which is generally used for boilers, turpentine stills, or like purposes. 
At Cedar Key two wells, drilled to 830 and 865 feet, have been aban- 
doned because the water contained so much salt that it was unfit for 
use. It is very doubtful if such wells would be satisfactory near the 
coast. However, near the eastern border of the county deep waters 
should be practically free from salt. There is little possibiHty of 
obtaining flowing wells anywhere in Levy County. 

Levy County contains a number of excellent springs, some of which 
are of considerable size. The Blue Spring near Bronson is estimated 
to flow 25,000 gallons, and the Wekiva Spring near Otter Creek over 
35,000 gallons per minute. The water from a small spring near 
Levyville is used for drinking, but none of the large springs are 
utilized. 



356 



GEOLOGY AND GEOUND WATEKS OE ELOBIDA. 



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1 








1 






1 








1 


!! ! 


i 




1 




§.2 

•si 


1 


i 

2 






c 








1 




o . 


i^ 


CO 


c 


c 


c 


c 


^^ 




III 




> 


■ 1 


e 
c 


1 






I 51 

11 


) 




1 


1 

< 


1 


1 


^ 

^ 


p 

'S 
"? 


a 


1 


c 

1 


1 
c 


c 
1 

1 





I 



.ts 



5.^ 



OP 

si 



as 



3.1 

as 

o o 






fi 



00 
.a 



^§ fi fi :s| 



1:3 ^ 



I 

s«a « 

pa cQ H 






C3 4)0 

(B _, <B 






d ® . 
<o ^ to 



II 

03 

a I? 

^ 03 



li'i a^l 

O tH (N l-H 



a* 



& a 



O O 



I a 



a s 
^ a 



.a I 



Nearest town 
or post office. 



Albion . 
Do. 
Do. 



Do 

Do 

Cedar Key. 

Do 

Do 



Double Sink.. 

EUzey 

Judson 

Do 

Do 

Do 

Lebanon 

Levyville 

Otter Creek. .. 

Do 



Nea; 



Nea. 



4mj. 



Neai 
5 mi. 

H4 
3 mil. 
8mii. 

Neai5 
l^m[) 

Neai-. 
8miB 

Near-. 



Do 

Montbrook. 
Morriston.. 

Do 

Williston... 

Do 



Protect-j 

ing 

clays 



No. 



Quality of water. 



Hard.. 
do. 



Yes- 



No. 



No... 
No... 
Yes.. 
No... 



do.... 

do.... 

do.... 

Brackish. 
Salt 



Hard 

do 

Soft 

Hard 

Hard, iron 

Hard, some iron. 
Hard 



Hard-. 
....do. 



...do 

...do 

...do 

....do 



No do. 

I do. 



Remarks. 



Starts in Pleistocene; draws Avater from 
Vicksburgian limestones. 



Second supply at 10 feet. 



76854°— -w 



Typical wells of Levy County. 



Ncarost tomi 
or post office. 


Direction and 


Oxraer. 


Driller. 


Date 
sunk. 


Type ot well. 


Use. 


Depth. 


Diame 


Casing. 


Eleva- 
tion 
above 


Head- 


t?rk 


1 


Protect 


Uemarte. 




Above 


Below 
snrlace 








W.S. Fletcher 

J.Medlin 

Peninsular Phosphate 

.....do 






Drilled 

Drivt 


Turpentine stUI 


Feet. 

i 

85 

865 
830 

52 
63 

47 

"o 

85 
90 
90 
45 


Iriches. 


Feel. 


Feel. 


Feet. 


Feet. 
65 
45 
60 

60 


Feet. 


Feet. 






Second supply at 10 feet. 






do 


•iamt°Hancocy::;:::: 


1892 
1892 

li 










50 

35 
70 




No.... 








60 
60 
8 






do 




P„ 




do 
















'='-C°^ 


do 




■brmtd-:;::::;. 




6 






Cedar I^y Town Co.. 




Abandoned . 












J mUe southwest.. 








830 






822 


















Driven 


Drinking 






36 
30 

1? 
7-8 

i 

16 
20 






Hard 






ij^UesToutheast: 
3 miles southeast.. 
8^n,Uessouthwe.t. 


?"wfsCdscoV.:::: 


James Hancock 


lii 


Turpentine stui 








"36' 


63 


yes.:: 


■■-.do 


















"G.w.iiVingVton::::: 


























...."°. 


175 
60 


No:::: 


Hard, iron 

Hard, some iron- 












Drilled 

Driven 

Driiitd:::;:::: 

do 














ymilesnorthw^st 




E.L.Freyermenth... 


1905 
1905 

1902 

!S 

1907 




79 

90 

40 
40 

22 








te^ik- 












28 






S"^"^' 


S|?^^^tni.or- 


James Hancock 


Turpentine stm 








Hard 






29 
■29 


21 
21 


^ 


90 

■ ■'eo' 


SS:::: 


do 

::::£:::::::::::: 

....do 














Montlirook 




James Hancock 










ittatfccoairLinc::; 

Preston King 


vrt----:: 




































WillistrafManufac'tur- 
ingCo. 




DrUled 


Manufacturing ice 






















' Water-supply Paper V. S. Geol. Survey No. 102, j 



GEOLOGY AliJ-D GKOUND WATERS OF FLORIDA. 357 

LIBERTY COUNTY. 
By G. C. Matson. 
GENERAL FEATURES. 

Liberty County occupies a large area between Apalachicola and 
Ochlockonee rivers. The surface varies greatly in altitude, ranging 
from 25 feet above sea level near the southern boundary to over 250 
feet on the uplands at the north. The broad terrace which occupies 
so large an area in the counties to the east and south doubtless extends 
into the southern part of Liberty County, and it is known to border 
Apalachicola and Ochlockonee rivers. Two other terraces of Pleisto- 
cene age occur in this county, but their distribution has not been 
ascertained. 

The uplands in the northern part of Liberty County form a plain 
rising over 250 feet above the sea and sloping gently toward the 
south. The major streams of the county have eroded broad vaUeys 
across this plain and small tributary streams have cut narrow steep- 
sided channels into it. In some localities the descent from this plain 
to the lowlands bordering the Gulf is abrupt, but elsewhere it is a 
gentle slope interrupted by broad terraces. 

GEOLOGY. 

The lowlands of Liberty County are mantled with gray Pleistocene 
sand. The uplands are thinly coated with residual sand, underlain 
by red and yellow sands and sandy clays belonging to the Lafayette ( ?) 
formation, which in turn is underlain by older rocks of Miocene and 
Oligocene age. The Miocene beds of Liberty County comprise soft 
clays and marls belonging to the Choctawhatchee marl, which under- 
lies the southern portion of the upland but probably does not extend 
to the northern border of the county. The Alum Bluff formation 
underlies the Ijaf ayette ( ?) formation in the north but farther south 
it passes beneath the Choctawhatchee marl. The Chattahoochee 
formation lies beneath the Alum Bluff formation throughout the 
upland portion of the county, but it is not exposed except along 
Apalachicola River and some of its principal tributaries. Beneath 
the Chattahoochee are the Vicksburgian limestones, but these rocks 
do not reach the surface in Liberty County. The lowlands forming 
the southern portion of the county are probably underlain by both 
the Chattahoochee and the Vicksburgian limestones, but there are no 
exposures and no weU records in that region, and hence no informa- 
tion can be obtained concerning these rocks. 

The thickness of the Pleistocene sands is probably in some places 
more than 50 feet, but they average less than 30 feet. The average 
thickness of the Lafayette ( ?) formation is less than 30 feet, though 



358 



GEOLOGY AND GEOUND WATEKS OP FLORIDA. 



locally it is greater than 50 feet. The Alum Bluff formation may be 
over 100 feet thick and the Chattahoochee over 250 feet, but there is 
little definite information concerning either of them. 



WATER SUPPLY. 

Source. — The Pleistocene sands yield abundantly within a few feet 
of the surface, the sands of the Lafayette (?) formation contain an 
abundance of water available for wells of moderate depth, and both 
the Choctawhatchee marl and the Alum Bluff formation should 
furnish large supplies of water, but neither of these formations has 
been penetrated in Liberty County. In adjoining counties the Chat- 
tahoochee and the Vicksburgian limestones furnish large quantities of 
water and the conditions are equally favorable for obtaining good 
supplies in Liberty County. 

Quality. — The water from the Pleistocene sands and the Lafa- 
yette ( ?) formation is usually soft, but all the older formations will 
doubtless supply hard water. 

Development. — Good supplies of water may be obtained at 10 to 
50 feet throughout the upland portion of Liberty County. In the 
lowlands similar supplies should be obtained in shallow wells. No 
deep wells have been reported, but such wells should be successful, 
though it is doubtful if the head of the water is sufficient to give flows, 
except perhaps in the stream valleys near the southern end of the 
county. The Vicksburgian limestones, the best water-bearing beds, 
should be reached in weUs at 400 to 600 feet on the upland and 300 
to 400 feet on the lowland. The head is sufficient to raise the water 
from these rocks over 20 feet above sea level, and hence wells drilled on 
the lowland may be easily pumped ; but in wells drilled on the upland 
the water level will be so far beneath the surface that pumping may 
be difficult. 

General water resources of Liberty County. 





Topo- 
graphic 
location. 


Source of 
water. 

\ 


Surface 
formation. 


ShaUow weUs. 


Town. 


Supply. 


Quality of 
water. 


Principal water 
beds. 


Bristol 


Plain 

...do 


Wells 

...do 


Sand 

...do 


Feet. 
20-40 

30-52 


Soft 


Vicksburgian lime- 
stone. 
Do. 


Estiffanulga 


...do 


Town. 


Deep wells. 


Quality of 
water. 


Depth to 
rock. 


Depth to 
water. 


Sewerage 


Depth. 


Supply. 


system. 


Bristol 


Feet. 
40 
52 


Large 

...do 


Hard and sulphur... 
do 


Feet. 
40+ 

.'524- 


Feet. 
15-20 
20-30 


None. 


Estiffanulga 


Do. 



















GEOLOGY AKD GKOUKD WATERS OF FLORIDA. 359 

MADISON COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Madison County occupies a roughly rectangular area in the north- 
central part of Florida, extending about 25 miles southward from 
the Georgia line. A large portion of the surface is more than 100 
feet, and some tracts are more than 150 feet, above sea level. A 
broad belt of swamp land extends from the south-central part of the 
county northward beyond the Seaboard Air Line E ail way. Lakes 
are numerous, both north and south of Madison, but none of them 
are large. Near the southern boundary of the county the valleys 
of Suwannee and Aucilla rivers are both less than 50 feet above sea 
level. 

GEOLOGY. 

Below the 100-foot contour the surface deposit of Madison County 
consists of a thin covering of Pleistocene gray sand, which obscures 
the underlying formations except where these have been locally 
exposed by erosion or artificial excavations. On the uplands there 
is a surficial mantle of gray residual sand underlain by red, yellow, 
and mottled sands and sandy clays, referred to the Lafayette ( ?) 
formation, though their exact correlation is uncertain. Rocks of 
Oligocene age underlie the formations just described. The Alum 
Bluff formation is represented by sands and clays which occur on 
some parts of the upland. The limestones of the Hawthorn forma- 
tion are exposed on Suwannee River near EUaville, and they doubt- 
less underlie the entire county at moderate depths. Beneath the 
Hawthorn formation lie the soft, light-colored Vicksburgian lime- 
stones. 

The average thickness of the Pleistocene gray sands in Madison 
County is less than 25 feet, and that of the sands and sandy clays 
referred to the Lafayette ( ?) formation is probably less than 50 feet. 
No well logs have been obtained, and it is impossible to give satis- 
factory estimates of the thickness of the older geologic formations. 

WATER SUPPLY. 

Source. — ^An abundance of water is obtained from the red and 
yellow sands of the Lafayette ( ?) formation, and some is said to be 
derived from the sandy clays of the same formation. The sandy 
beds of the Alum Bluff formation doubtless furnish water for some 
of the wells, but it is difficult to tell from the well records whether 
the supplies come from this formation or from the overlying Lafa- 
yette ( V) formation. The Hawthorn formation yields large quanti- 
ties of water and may supply the deeper wells of the county. The 



360 GEOLOGY AND GEOUND WATEKS OF FLORIDA. 

best sources of water in Madison County are the Vicksburgian lime- 
stones, though it is doubtful if many of the wells are deep enough to 
reach these rocks. 

Quality. — ^The water from the sands of the Lafayette ( ?) formation 
and the Alum Bluff formation is generally soft, though locally it may 
contain enough mineral matter to be moderately hard. The Haw- 
thorn formation yields hard water, and similar supplies are to be 
expected from the Vicksburgian limestones. Deep wells in the last- 
named formation should encounter sulphur water containing con- 
siderable quantities of mineral matter. 

Development. — The shallow wells of Madison County obtain enough 
water for ordinary domestic and farm uses. They range in depth 
from 10 feet to nearly 50 feet, and wells less than 30 feet deep are 
common. The water level lies so near the surface that pumping is 
easy, and the supplies should be entirely satisfactory except where 
there is danger of contamination by impure surface drainage. 

Few of the deeper wells exceed 100 feet, though some are more 
than 200 feet deep. The supply is large, and although the water is 
hard it is regarded as satisfactory. The presence of clays above the 
water-bearing beds prevents pollution by surface water, and hence 
these wells are suitable for domestic supply. 

Springs are numerous in Madison County, but most of them are 
small and few are extensively used. Among those noted was one 
near EUaville and one 3 J miles west of Pinetta (the Cherry Lake 
Spring). The latter is used for bathing and drinking, and, although 
the flow is small, a bathhouse has been constructed. The water con- 
tains some sulphur and its temperature is 68°. 















Nearest 
town. 


Direction and 
distance. 


Depth 
to 

princi- 
pal 

supply. 


Pro- 
tecting 

clays 
present. 


Quality 

of 
water. 


Remarks. 


Ellaville 




Feet. 








Do 


Near 




Yes... 
Yes... 


Hard.... 

...do 

do 




Do 

Greenville 


do 

..do 


'"m" 
"'ios'" 

65 

'""'76" 

""99" 
143 




Do 

Do. 


J mile southwest... 
... do 


Yes... 


...do 

do 




Lee 


Near 


Yes... 
Yes... 
Yes... 
Yes... 
Yes... 
Yes... 
Yes... 
Yes... 
Yes... 

Yes... 
Yes... 


...do 

...do 

...do 

...do 

...do 

...do 

Soft 

Hard.... 
...do 

...do 

...do 

do 




Do 

Do 

Do 

Do 


do 

do 

do 

do. 




Do 

Lovett 


4 miles east 

Near 




Do 

Madison 


3 miles east 

L 


Incmsts boilers. Yields 92 
gallons per minute. 


Do 

Do 

Do 


r 

12- miles west 

do ! 

12 miles south l 


""52" 


Do 


Yes... 
Yes... 
Yes... 
Yes... 
Yes... 
Yes... 
Yes... 
Yes... 
Yes... 
Yes. . . 
Yes... 
Yes... 
Yes... 


...do 

...do 

...do 

...do 

...do 

...do 

...do 

Soft 

Hard.... 

...do 

...do 

Medium. 
...do 




Do 

Do 

Do 

Do 

Do 

Do 

Pinetta 


IJ miles west | 

do 1 

9 miles south j 

2 miles northwest.. \ 

do 

J mile east 

Near 


"'i52'" 

■■"35"" 
120J 




Sirmans 

Do 


2 miles east 

i mile north. . . 




Do 

Red Oak 

Do.. 


do 

2 miles north 

. . do 


87 
58 
68 











76854°— WSP 31*-13. 



Typical wells of Madison County. 





Direction and 
distance. 


owner. 


Driller. 


Date 
sunk. 


Type of 
well. 


Use. 


Depth. 


Diam- 


Casing. 


Eleva- 
tion 
above 


Head- 


Depth 


3: 






town. 


^'^e°a™ 


s^u?!re 


rook. 


Remarks. 






Milliner. 








Turpentine still 

General... 


Feet. 
100 
100 

205 

104 

107 

lOS 

87 

145 
240 

115 

i 

m 

35 
1 


Imhes. 
\ 

2 
2 
2 


Feet. 


Feet. 


Feet. 


Feet. 


Feet. 


Feet. 














1900 

1900 

190S 
1908 
1907 
1907 

1007 
1905 
1906 

1907 

1900 
1907 
1900 

1901i 
1907 
1907 
1907 
1907 
1907 

1905 

1904 


Drilled.... 

...do 

...do 

...do 

;;;do;;;;;:: 
;;;do;;:;:;' 
::;t;;;;:: 
;;;t;;;;:: 

...do 

...do 

..-do 

;;;do;;;::; 
:::do;;:;;;. 
:::t:::::: 

...do 

...do 


100 
200 


99 


64 
64 


60 

40 
45 
50 

50 

46 

so-?S 


12 

12 

IS 

90 
60 


"'iiii' 
""m 

65 


Yes... Hard... 
Yes do.... 

-Yes::: ;;;£;;; 

do.... 

yS;;; ::;dS:;;:. 
?S:;::;;t;;;: 
?S;;;:::t;;;; 
?S;:; XV.;:: 

Yes do 

Yes do 

Yes do 

'Yes;;; ::;do;:::: 

Yel do::::: 

^et ;l^:;;;: 
^e^ t:;;; 
^?t &.::: 
^?s t::::. 
\T. ''dr."; 






jmile southwest.'! 


do 


do 






M.A;McDi£ji"ei;::::;: 


Bind & Pay™;;..:.:. 












;;;;;^e;;;;;;;;;;;;; 


100 
60 

69 
^U 

BO 




















Do 


:;:::t:::::::::::; 


W.J.Greer 

LeeGlnninECo 

G.B. Haven 


■jack Newman 
















Do.. 














Wells&Shaw 










36 


143 






do 










Turpentine still 

General 








Do. 


3mUeseast 


D. M. Wood 


Bond& Payne 












City and railroad sup- 
D?afnage 


175 


95^S5 


Inerusts Ijoilcrs. Yields 92 
giiUoiis per minute. 


Do 


SS---' 


R.V.Dial 

do 

a. P.Kelley 

Merchants Hotel 

H.M.Taylor 

ii. P. Thompson 


J T Sharpc 


52 


■■"52" 




do 


Drii^in^g 


















15 






F. D. Ferreli 


Disposal of.sewage 












'-^";r^-^'^' 




iS 
'I 

120 






.15 


70 
3o 

m 

None 
120 


ll2 

58 




















do 










Drainage 














Ge'neral 






















145 
10 
30 
14 

! 










■Tu^^h^stui;;;:::: 










2 miles east 

.'.".r.°:!^::::;:- 




Bond & Payne 




















leSf.iand:;:::;: 


...■.do.......;;;;:::::: 








KedOak.... 


DrinliinK 


59 





























' 319—13. (To face page 360.) 



MADISON COUKTY. 



361 







i" 


a^ 






-2 . . ^'g: 






^1 1 ^1 


g 


1 


t 


c§ 


bXJ-U " W)0 


M 


s 


i^ 1 i^ 


.& 


^ 






MM KiM 


C3 ® 




O > O OCQ 


W O 




:2; iz; ;^ 


Jz; 


■^ ^: 


, kO • • 














&3| 


1^ : : 








^•;2 s ;ss 




^"^ i lik 










Aver- 

thick- 
nessof 
sand. 


^(M Op iooo • 

1 ir : 




K^*-! 


: : : 








.-a^ 










^^ 


"H d o o +i 


T^ 


1 


^•s 


c3 xS'V'a 


^ 


03 


>> 


S i : 




03 


1 


XJ . . 




TJ 


1 


^ -ceo o 


X2 


ft 




«^ : : 


C5 


-^ 


6 


.§ ii 


CO 






k 


1^ 








ft 






















fl : : 








.&^ 


5 : : 








1^ 


g . . . 

CJ o o o o 


d 




p^i 


^ ; : 
























42 


>>H 


S ' • 


























^ 


"^^ 


tj o o o o 


d 


1 


C^-o 


pm : : : : 


•r) 










03 








>> 


; : : ©frt 


: 




P< 


eg t3't3 S o 


o 




S 


-^3 




5 


fR : :aiO 


: 


a 
& 








1 : ^ :S2 


7 

kO 




ft 






w I I a! ! 




(D f^ 


i>. . : >> . 










la 


a ^;a^ 


^. 




.2 6 ;53 




V, 


'^c^ : : -"a 




SI 


"|: iil 




P 03 


Pl^^l 


d 


02 O 




III 


; w) ; ' w) 






1 










1 


111 


i.B 


03 

a 






W O^H 


]PH 


5 






822 

<D (» 3 



§* 



&a 



IS 

02 



a o 



•3 £f 



ft ^ 



ft 



ft 



Wl © i 



03 o a 

>.a^ 

'- § 
Sgac^ 



CO O ' 

Pk. O-^ 03 



.§a 
w 



^1 

O Ph 
CQ 



•II 






§i ©■ 






362 GEOLOGY AND GROUKD WATEES OF FLORIDA. 

MANATEE COUNTY. 

By G. C. Matson. 
GENERAL FEATURES, 

Manatee County occupies the greater portion of the area between 
Tampa Bay and Charlotte Harbor and extends more than 30 miles 
inward from the coast. Some long narrow islands or keys are sepa- 
rated from the mainland by shallow bays and sounds. Near the 
coast the land rises from a few feet to about 25 feet above sea level 
and forms an extensive plain representing the former extension of the 
sea upon the land. This terrace appears along some of the streams 
but is not so well developed here as farther north. Another terrace 
40 to 60 feet above sea level is widely developed. The northeastern 
part of the county lies more than 50 feet above sea level and perhaps 
some of the higher hills near the northeastern corner of the county 
have altitudes of 100 feet or more. The drainage of the county is 
chiefly through Manatee, Little Manatee, and Myakka rivers. Near 
the northern boundary there are several good-sized lakes, and ponds 
and swamps are common throughout the southern half of the county. 

GEOLOGY. 

Nearly the entire surface of Manatee County is covered by gray 
sands of Pleistocene age, underlain by yellow or brown sands which 
closely resemble the surface sands and probably owe their color to 
iron oxide. Near the southern boundary the Caloosahatchee marl 
may underlie the surface sands, but in the absence of exposures and 
satisfactory well records their existence in that area can only be 
inferred from their presence on the lower course of Myakka River. 
Upper Oligocene limestones, lying approximately at the horizon of 
the Alum Bluff formation, occur on Manatee River in the vicinity 
of EUenton. They are covered by a few feet of fuller's earth, which 
probably belongs to the same formation. The Tampa formation 
may underlie the county but is not exposed and can be inferred only 
from its relation to the Alum Bluff formation. Beneath the Tampa 
formation lie the Vicksburgian limestones, which have been reached 
by wells at several points along the coast beyond the southern limits 
of the county. 

The surficial sands of Manatee County are comparatively thick, 
though locally, as in the vicinity of Ellenton, they may amount to 
only 2 or 3 feet. The maximum thickness is at least 50 feet and the 
average is probably greater than 25 feet. The Tampa and Alum 
Bluff formations attain a thickness of over 250 feet in the vicinity of 
Ellenton and are probably more than 200 feet thick throughout a 
large part of the county. The base of the Vicksburgian limestones 



MANATEE COUNTY. 



363 



is not known to have been reached in any of the deepest wells and it 

is safe to infer a thickness of several hundred feet for these limestones. 

The following log shows geologic conditions on Terra Ceia Island: 

Log of well of A. D. Wright, Terra Ceia Island. 



Soil and clay 

Marl 

Fuller's earth 

Sandy clay 

Soft rock 

Clay 

Rock 

Clay 

Soft rock 

Clay 

Rock 

Clay 

Rock..... 

Clay 

Sand, black 

Limestone, white 

Marl 

Limesljone 

Clay 

Limestone 

Clay 



Depth. 


Thickness. 


Feet. 


Feet. 


4 


4 


2 


6 


10 


16 


16 


32 


9 


41 


22 


43 


6 


49 


4 


53 


3 


56 


1 


57 


2 


59 


1 


60 


2 


62 


1 


63 


2 


65 


5 


70 


47 


117 


2 


119 


10 


129 


4 


133 


' 


136 



Rock, soft 

Clay 

Rock, soft 

Rock, with some soft streaks . . 

Clay 

Rock 

Clay 

Sand 

Clay, soft 

Clay, very hard 

Limestone, white 

Clay, blue; containing several 

thin layers of rock 

Clay, containing some very 

hard layers 

Rock, very hard 

Clay, white: with some thin 

layers of hard rock 

Rock, hard 

Limestone, soft porous 



Depth. 



Feet. 



1 
18 
15 
12 

1 

5 

6 

2 

2 

18 

37 
9 

4 

5 

47i 



Thickness. 



Feet. 
142 

148 
149 
167 
182 
194 
195 
200 
206 
208 
210 

228 

265 

274 

278 



The artesian water beds were found at 289 feet. The rock con- 
tained in the above section is largely limestone, though it contains 
some thin beds of chert. The clay is apparently a soft marl. 

In the vicinity of Palmetto and Bradentown the first strong flows 
are encountered at about 260 feet and this is regarded as the approxi- 
mate depth to the Vicksburgian limestones. Doubtless these rocks 
occur a few feet above the water bed. 



WATER SUPPLY. 

Source. — ^The surficial sands supply large quantities of water 
throughout the county and the upper Oligocene limestones are also 
locally important water-bearing beds. The best aquifers of Manatee 
County are the Vicksburgian limestones, which supply large quan- 
tities of water suitable for domestic use or for irrigation. Good flowing 
wells have been obtained from the Vicksburgian limestones at differ- 
ent points along the coast. 

Quality. — ^The surficial sands yield soft water suitable for all 
purposes, and are generally regarded as satisfactory. The upper 
Oligocene limestones supply hard water which contains hydrogen 
sulphide at some places. Hard sulphur water is found in the Vicks- 
burgian limestones and, in some locaUties, salt water also. 

Development. — Throughout a large part of Manatee County soft 
water can be obtained at depths ranging from 5 to 25 feet and these 
supplies are extensively developed, especially for domestic and farm 
uses. A few drilled wells may reach a depth of 50 to 75 feet, but in 



364 



GEOLOGY AND GROUND WATERS OF FLORIDA. 



such places satisfactory water-bearing beds can generally be found 
nearer the surface. The flowing wells range in depth from 200 to 
over 500 feet and furnish large quantities of water. In the northern 
end of the county the head is sufiicient to give flows at a height of 
approximately 32 feet above sea level, and toward the south the 
altitude to which the water will rise slightly increases. A large 
number of flowing wells have been drijled in the vicinity of Manatee, 
Bradentown, EUenton, Terra Ceia, Oneco, Sarasota, Fruitville, and 
Parish. Flows could doubtless be obtained along the entire coast in 
this county. Wells on low ground in the interior of the county might 
obtain flowing water, but in most places the water would not have 
sufficient head to reach the surface. However, even in the higher 
parts of the county the sulphur waters from the Vicksburgian lime- 
stones will rise near enough to the surface to be easily pumped. 

Bradentown has a pubhc water supply obtained from two 
drilled wells 410 to 427 feet in depth. The system is said to give 
excellent satisfaction. The quantity of water is ample and its 
quality is good. 

General water resources of Manatee County. 





Topo- 














Shallow wells. 


Town. 


graphic 
loca- 
tion. 


Source of water. 


Surface for- 
mation. 


Depth. 


Supply. 


Quality 

of 
water. 


Principal 
water beds. 


Bradentown. . 

Ellenton 

Manatee 

Palmetto 


Plata.... 

...do 

...do 


Public supply, drilled 
wells, driven wells, 
and cisterns. 

Drilled and driven wells, 
and cisterns. 

do 

do 


Pleistocene.. 

do 

do....... 

do 


Feet 
8-75 

8-15 

18-80 
25-65 


Ample. 

...do... 

...do... 
...do... 


Soft... 

...do... 

...do... 
...do... 


"Peninsu- 
lar" lime- 
stone. 
Do. 

Do. 
Do. 




Deep wells. 


Aver- 

tWck- 

ness 

of 

sand. 


Depth 

to 
water. 




Town. 


Depth. 


Supply. 


Head 

above 

sea. 


Quality 
of water. 


Remarks. 


Bradentown 


Feet. 
200-440 
400± 
364^10 

4004- 


Large... 

...do 

...do 

...do 


Feet. 
20± 
10-<- 
20± 

lO-h 


Sulphur. 

...do 

...do 

...do 


Feet. 

10-75 

10-1- 

10-2.5 

10-30 


Feet. 
3-15 
4-8 
^15 

2-10 


No sewerage system. 


Ellenton . 


Do. 


Manatee 


Reported some flowing 


Palmetto 


wells at 60 feet; no 
sewerage system. 
No seweraee svstem. 





































N 
or 


)epth 
rock. 


Depth 
to priQ- 

cipal 
supply. 


Quality of water. 


Depth 
to sec- 
ond sup- 
plies. 


Yield per 
minute. 


Remarks. 


Bk 


Feet. 


Feet. 

347 

370± 

60,80 

110,180 

60,80, 

110,180 

400 

300 




Feet. 


Gallons. 
150 

500 




do 








do 








do 




Do 










t- 


do 

do 




100 














350 
Many. 
Many. 
200 
Many. 
Many. 
Many. 
Many. 
Many. 
Many. 
Many. 
Many. 
Many. 
Several. 
Many. 
































180 
300-375 
365 






Pumped with air lift. 




... .do 




Cor 
Ell 





Sulphui" some salt 

Sulphur 


140 


Salt water at 90 to 100 feet. 




370 
370 
200 


do 








do 










200 






..... 

Sulphur 








453 


Sulphur; very strong:. . 


3?1 








293 
350 


do 


293+ 
350+ 




: 


do 




Lor 
































Mai 


"■38" 


400 
263 
350 
320 
2 

""175" 
2104 
300 
348 


Sulphur 




Many, 

Fev^. 

100 

Many. 

40 

150 

Many. 

Many. 

150 

Few. 




do 










50, 150 






Sulphur 






do 








do 

Hard 




Protective clay present. 


















Hard 
















505 
15,30 


460 

300 

300 

320+ 

300 

292 

300+ 

400 

286+ 

285+ 


Hard . 








do 














100 

150 

40 

30 

Many. 

140 

55 

93 

Many. 




' 


Hard 






?I? s 








Sulphur 


120 




Pal 


'"273" 




do 






do 








Hard, sulphur 


125 














200 
185 


450 


Sulphur 


Several 
Several 






Hard 








100+ 




Par 


















No rock to bottom of easing. 







500± 

300i 

300-320 


Hard 


300 




Forms scale on casing. 






Many. 






Hard 




No rock to bottom of casing. 












Sar 





Hard 

























400 ± 
400± 












Sulphur 




Many. 














90 
■"226' 


72 

350 
400± 

210 

208 
506 
325 
258 
360 
309 


Iron sulphur 


40-128 
150+ 








Hard, sulphur 














Sulphur 


184 


150 
Very many 
Very many 
300 
Very many 
Many. 
Many. 
1200 

250 
Many. 

125 
Many. 
Many. 
Many. 
Many. 




Ter 




Channel near bottom. 






Do. 






260 






Sulphur.. . . 






Hard, sulphur 

Sulphm*.. 


Several 
290 






do 






70 


300 
350± 


Hard,sulphur,magnesia 
Sulphur 


188 
Several 






...do . . 








340 
332 
260 
256 
289 




102 
244 






Sulphur 






do 






do 


177+ 
67- 






do 
















c Bv barometer. 









Typical wells of Manatee County. 



IJ miles southeast 
t miles soutlieast 



2 miles northwest. 

3 miles north 

ImUeeast 

Similes north.... 



li miles northwest 
mile north..!... 



i mile northeast. 
Tmile north'.!;;! 



Maj. A. J. Adamsa... 

Barrack 

Bradectown Water- 



L.S. Elliott.... 
J.A.Fletcher.. 
H. W. Fuller... 
Manatee L. & I 



D. W. Turner.. 
Mrs. J.C.Brutt 
CD. Fuller... 



D.M. Gibbs 

Eason& Steams. 
A.W.Wallace... 



Excelsior Ice C 
S.C.Gates a.. 
Oscar Krause . 



A. E. Stebbins.. 
Wm. Richman.. 
J.H.Viser 



G.I. Dickieo 

W. O. Han-ison 

S.S. Lamb 

Manatee Lemon Co.<^ 
Schuyler Poitesent a 



C. A. WimiettV. 

..-.do 

Owner 



W. D. Holcomb.. 

E."j; Pettigrew... 



Barville 

Chas. Blood ( 

E;B."Dalea. 
Frank F. 






C. F. Hobarta! 

Howard & Kennedy o 

E. S- Hubbard a 

A. G. Lisles 

J. G. Powersa 

Mrs. E. A. Robb 

Stephens & Weaver.. 



. Wimsett. 
."wiiriscU." 



Pleistocene- 
Pleistocene. . 



Mcksburgian limestone 

Vicksburgian limestone 
....do 

Vieksburgiaji 
....do 

Vicksburgian 
Vicksburgian limestone 



Vicksburgian limestone 
V ieksburgian 



Drilled.. 
i>ri;iied;; 



Drilled., 
ririiiod!! 



Lrigation, house. 



Irrigation, house, £ 



Domestic and stock. , 

Hotel 

Irrigation 



Domestic and inigation 

b omestic and irrigation 

Domestic 

Irrigation 



Irrigation, etc 

Domestic and irrigation 



Ice manufacturing.. 



Public supply , dome 

tic, and irrigation. 

Domestic and irrigati 

Irrigation 



-l 



300± 
300-320 
300-320 



llSy! 



Forms scale in hoUers. 



Pumped with air lift, 
water at 90 to 100 1 



Protective clay present. 



Hard 

Siiipliur^! 



Many. 
"'"'i66+ 



No rock to bottom of easing. 
Forms scale on easing. 

No rock to bottom of easing. 



SulpW 

Hard, sulphur. 
Sulphur 



Very many 

300 

Very many 



I Water-Supply Paper U. S. Gool. 



GEOLOGY AND GROUND WATERS OF FLORIDA. 365 

MARION COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Marion County is in the north-central portion of the peninsula 
and includes a portion of the central lake region. The surface is 
very irregular, the higher hills rising above 150 feet and the lowest 
valleys being less than 50 feet above sea level. Much of the drainage 
is through underground channels in the limestone. At many points 
of emergence the underground streams form very large springs. The 
existence of the underground channels is shown by numerous sink- 
hole depressions, which may contain lakes but which are usually dry. 
In some localities the water that enters the depressions drains to the 
underground channels through open holes, but in most places it 
escapes by seepage through the sands. 

GEOLOGY. 

Gray sand, largely derived from the weathering of the Alum 
Bluff formation, mantles the surface of Marion County and is com- 
monly underlain by yellow or brown sands. A narrow strip along 
the eastern border of the county is underlain by shell marls of Pliocene 
age (Nashua marl), but it is doubtful if these beds extend far from 
St. Johns River and they are so thin as to be of no hydrologic value. 

In the eastern half of the county the limestones, sands, and clays 
of the Hawthorn and Alum Bluff formations occupy large areas. 
The Vicksburgian limestones immediately underlie the surface sands 
in the western part of the county, and they dip eastward from the 
vicinity of Ocala, passing beneath the Hawthorn formation. 

The average thickness of the gray sand is probably more than 20 
feet, though over large areas the underlying rock is near the surface. 
In favorable situations the thickness of the yellow residual sand may 
amount to over 20 feet, but it is usually only a few feet. The Miocene 
and Pliocene beds are probably less than 25 feet thick. The Haw- 
thorn formation may reach a thickness of more than 100 feet near 
the eastern boundary of the county, but it thins to a few feet farther 
west. The Vicksburgian limestones probably extend to a depth of 
several hundred feet. The following log of a well at Ocala was 
furnished by Sellards: 

Description of samples from well at Ocala. 

Depth 
in feet. 
Limestone, soft, white, granular; apparently Vicksburg; contains 

many Foraminifera and fragments of shells 50 

Same; possibly somewhat harder bi^t not materially different 75 

Same , , 100 

Limestone like above predominates; fragments of blue-gray lime- 
stone like the following are included , , . , , . IIQ 



366 GEOLOGY AND GKOUND WATEKS OF FLOEIDA. 



Depth 
in feet. 



Limestone, hard, blue-gray predominates; some fragments of the 
white limestone; unbroken piece indicates that these blue frag- 
ments are embedded in a light-colored matrix 130 

Limestone, white; possibly somewhat more granular but otherwise 

not differing from above 160 

Same 200 

Limestone, a gray or light blue-gray, compact; not unhke that at 

130 feet, although possibly harder 260 

Limestone, white, granular 300 

Limestone, gray, very compact; sample contains one very porous 

piece 350 

Limestone, granular, white 375 

Limestone, porous, white; appearing nearly cream yellow in the 

powdered form 430 

Similar to last in character but darker, nearly cream yellow 440 

Limestone, brown, apparently rather porous; darker than last 445 

Limestone, brown and light colored mixed, the brown predom- 
inating; a few grains of siHca 460 

Limestone, dark brown, porous 480 

Limestone, dark brown 500 

The white limestone with some gray to 375 feet is doubtless Vicks- 
burg. The light to dark-brown limestone found below may belong to 
the same group. 

WATER SUPPLY. 

Source. — The surficial sands, especially the yellow residual sands, 
supply water to shallow wells. Deeper supplies come either from 
limestone and sand of the Hawthorn formation or from the Vicks- 
burgian limestones, the Vicksburgian being by far the best source 
of supply, though good wells may also be obtained in the Hawthorn 
formation. 

Quality. — ^The surface sands yield soft water. The water from 
Hawthorn and Vicksburgian rocks is invariably hard; some wells 
carry hydrogen sulphide and others are excessively salty, but fortu- 
nately this latter condition is rare. 

Development. — ^Many wells of Marion County are less than 100 feet 
in depth, yet they supply an abundance of water. Few exceed 20C 
feet. No flowing wells are apt to be obtained on the uplands in this 
county, but the head below the surface is usually less than 50 feetj 
though, locally, it may amount to nearly 100 feet. This head should 
permit the successful operation of deep- well pumps. Near St. Johns 
River it should be possible to obtain good flowing wells on low ground, 
and though the exact head of the water is not known it would prob- 
ably rise from 20 to 30 feet above the river. The water would con- 
tain considerable sulphur and other mineral matter but not in 
quantity great enough to interfere with its use. 













Protect- 
- ing 

clays 
present. 


Qualitv of 
water. 




Nearest town 
or post office. 


Dii-ecti( 
dista 


Remarks. 




Yes... 
Yes... 
Yes... 
Yes... 
Yes... 

Yes.i.' 

"Yes.";; 

"Yes.'!.' 

Yes. . . 

No.... 
Yes. . . 


Hard 






1^} miles I 

do... 

2 miles w 
Near.... 

2 miles w 
Near.... 
1 mile noj 
lm)le...r 
Near j 

3 miles ea 
Near. ..r 




Anthony 

Do 

Do 


do 

do 

do 

do 

do 

do 

Hard.sulphnr. 

Hard 




Do .... 




Do 




Do 




Belle view 

Citra 


Several minor water beds. 

Casing extends from bottom of 12-foot 




Dunnellon 

Do 


Sulphur, iron . 
Hard 


pit. 
Some minor water beds; large yield. 








Sulphur and 

lime. 
Hard 




Do . 






li miles 1 
do... 


burgian limestone: supply large. 




do 

do 

do 

do 

do 

do 

do 

do.... 




Do 

Do 




Do 


- 




JtUiette 

Do 


2i miles r- 
do ■ 


Tncrusts boilers. 


Do 


1^ miles r 
Near....- 
3 miles w 
1 mile eai 

I mile noi 
Near...., 

II miles t 
Near....^ 

do...- 

do...- 

do...- 

do...- 


Kendrick 




Lake Kerr 

Leroy 


Yes... 


do 


Incrusts boilers. 




Large supply. 




Yes... 


Hard .. 








do 

do.... 




Martin 








do 








Mcintosh 

Do 

Do 

Do 




do 

do 

do 

do 


No minor supplies. 
Tncrusts boilers. 




1 mile soi 
Near.... 

1 mile no • 
East....- 


Montague 

Oak 


Yes... 


do 

do 

do 

do 

do 

do 

do 

.. . do 


Ocala 




Do 




Do 


Second supply at ]50 feet. 


Do 


Near....- 
Jmileeaj- 
1 mile no 

1 mile so 

2 miles s( • 
East !• 


Do 




Do 








Do 

Do 


No.... 


do 

do.... 










No.... 
Yes... 
Yes... 


Soft 










Hard 






Ui miles 

do... 

J mile nc 

1 mile nc 






do 

do 

do 




Do 

Do 






Yields 100 gallons per minute. 
















Hard, sulphur. 
Hard 




Do 








if mile nc " 

Near.... 

i mile ear 

Near....- 

1 mile sor 

2 miles w • 
Near....r 
1^ miles ! - 
Near....- 

do- 






Yes... 

'Yes."." 
Yes. . . 
Yes. . . 
Yes... 
No.... 
Yes. . . 


do 

Hard, sulphur. 
Hard 




Rock Springs . . 
Silver Spring... 
Span* 




do 

do 

do 

do 

do 

do... 




Do 




Do 




Do 




Do 




Spring Park.... 
Weirsdale 


Tuf^rusts boilers. 


Ye'! 


do 




Zuber i mile no 


Yes. . . 

1 


do 








76854 


°— wsp a: 





Typical ivells of Marion County. 



Depth 
supply. 



K, 



&.. 



Sprine i 
Weirstlit 
York... 



French Phosphate Co 



McGeehee & Mayo.. 

S. H. Whiteo 

Atlantic Coast Line. 



Dunnellon Phosphal 



Dulton Phosphate Co 



J. H. Harvey 

...-do 

D, Baskin 

J. H. Haivev 

....do : 

E. L. Freyermeuth.. 

j!d^ Alien!";!;;!!! 



Baxter Moiris 

Zack Graham 

W. P. WiUiamson.... 
Clark, Ray, Johnson, 



McDowell Crate & 
Lumber Co. 

Biilluok<S: Snoit 



Ofula Bottling Works 

Co. 
Ocala Ice & Packing 

Co. 
Ocala Water Co 

Wefiert & Maynard . . 



E. L. Freyermenth. 
Mciver'& MacKay ! ! 



Mclver & MacKay.. 
E. L. Freyermenth.. 



H.F.Lloyd... 
J. H. Harvey.. 



Drilled!; 



Washinfj phosphate . 

City supply 

Domestic 



G eneral . . . 

....do 

Phosphate 



Public. 
Domestic 



Disposal of sewage . 



Household . 

General 

Disposal of s 
Household . 
General 



and sewagi 
Ice manufaci 

City supply . 



Sawmill and turpen- 

SawmiU..." 

Household 



Open duf; 
DUR 



=751 



Sulphur, iron . 

Hnri 

Sulphur and 

Hard.! 



Inciusts boilers. 
Laree supply. 



Incrusts boilers. 



Yields 100 gjllous per n 



Hard 

do 

Hard.suJphui 



1 Water-Supply Popei- U. S. Oeol. Survey No. 102, p. 250. 



MAKION COUNTY, 367 

Springs are numerous and some of them are very large. Silver 
Spring, a short distance from Ocala, is the largest and most important. 
This spring is supplied by water which emerges through several 
openings into a basin-shaped depression having an area of several 
acres and a depth of over 35 feet. The volume of flow is about 385,000 
gallons per minute and this is sufficient to form a stream — Silver 
Spring Run — which is large enough to float good-sized passenger and 
freight steamers. The stream has a depth of about 8 or 9 feet in the 
center of the channel and a length of nearly 10 miles to its junction 
with Ocklawaha River. The water from Silver Spring is noted for 
its clearness; objects on the bottom of the pool are distinctly visible 
and fish may be seen swimming about in the run. The source of this 
spring is the porous and cavernous Yicksburgian limestones; much 
of the water enters the ground within a few miles of the spring, and 
as it does not travel far through the soluble limestones it is only 
slightly hard. 

Blue Spring near Juliette supplies a large stream, estimated at 
nearly 350,000 gallons per minute. Orange Spring, one-fourth mile 
north of Orange Springs, has a comparatively small discharge esti- 
mated at about 2,240 gallons per minute; the water contains sulphur 
and is used for bathing. A saline spring near Norwalk has a flow 
estimated at 84,000 gallons per minute. 

Both Ocala and Dunnellon have public water supplies which use 
water from wells drilled into Yicksburgian limestones. The water 
is reported to be moderately hard, but the supplies are adequate for the 
needs of the towns and the quality is satisfactory, though the water 
from the deep well at Ocala contains some salt. In both cities shallow 
wells are used by individual families, but the sanitary character of the 
water is doubtful. The deep-well water should be safe, provided care 
is taken to prevent surface water and sewage from entering the water- 
bearing rocks. 

76854°— wsp 319—13 24 



368 



GEOLOGY AND GROUND WATERS OF FLORIDA. 



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MARION COUNTY. 



369 





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370 GEOLOGY AND GKOUND WATEES OF FLORIDA. 

MONROE COUNTY. 
By Samuel Sanford. 
GENERAL FEATURES. 

Monroe County comprises the extreme southwestern part of the 
Florida Peninsula and the keys south and southwest of the Bay of 
Florida. Nearly all the mainland is swamp and much of it is within 
the Everglades. Except for the sandy strip at Cape Sable and the 
tracts of prairie near Flamingo, there is very little arable land. The 
principal settlements on the mainland are near Flamingo and at the 
mouth of Shark Eiver. The only inhabitants of a large area are 
Indians. On the keys there are settlements on Key Largo, Planta- 
tion Key, Long Key, Grassy Key, Key Vaca, Big Pine Key, and Key 
West; on the last named is the city of Key West, the county seat 
and the only large settlement in the county. 

The mainland lies very low; there is probably no point with an 
elevation of 20 feet above tide, and the average elevation is less than 15 
feet. Most of the coast is a swamp fringed with mangrove islands. 
Whitewater Bay, though over 20 miles long, contains few wide 
stretches of open water and is largely a maze of shallow lagoons and 
mangrove islets. 

GEOLOGY. 

In the Everglades peat beds rest on sand, marl, and the Lostmans 
Kiver limestone. The latter underlies the mainland coast and ex- 
tends an undetermined distance inland and under the Bay of Florida. 
Marls, more or less peaty in places, form the coastal islands north of 
the bay. Their maximum known thickness is 15 to 20 feet about the 
mouth of Shark and Lostmans rivers. Quartz sands are not conspicu- 
ous north of the bay except at Cape Sable and on scattered beaches 
facing the Gulf. South of the bay the Key Largo limestone outcrops 
or underlies sand or limy marl on the keys of the main chain between 
Bahia Honda and the east line of the county; and from Big Bahia 
Honda to Boca Grande the surface or subsurface rock is the Key West 
oolite. No rocks older than Pliocene outcrop in the county. The 
character, thickness, and relations of the Pliocene, Miocene, and 
Oligocene beds, as shown by drilling, has been discussed elsewhere 
(pp. 173-174). 

WATER SUPPLY. 

Source and quality. — ^The only wells on the mainland yielding pota- 
ble water are those in the sands of the beach ridges at Cape Sable. 
No deep wells have been sunk, and it is doubtful if the Oligocene 
formations contain good water or if higher formations will yield flows. 



MONROE COUNTY. 371 

Along the keys south of the Bay of Florida fairly good water is 
found in the Pleistocene limestones, the best being in the key having 
the largest extent of land above high tide — Big Pine Key. On all the 
keys the occurrence of fresh water, the quality of which varies greatly, 
is limited to a zone a few feet or even inches thick, near sea level. 
The water in the potholes and natural wells on most of the keys is 
decidedly brackish because of the entrance of sea water through the 
honeycombed limestones. 

Development. — Springs have been reported on Big Pine Key and 
Key West and in the sea bottom elsewhere, but no true springs were 
found. The ''springs" used by settlers are natural wells a few feet 
deep. There may be a perceptible surface flow from open passages 
on Big Pine Key duriag the rainy season, when the fresh-water level 
is high, but the proved occurrence of salt water below the fresh for 
hundreds of feet and the permeability of the sands lying below the 
surficial oolite and coralline limestones make it certato. no deep- 
seated springs of fresh water occur along the keys. 

No wells on the mainland except those at Cape Sable yield fresh 
water. Wells near Flamingo find salt water in the limestone below 
the marl. The best of the Cape Sable wells are near Middle Cape 
and are but 5 feet deep. The water from them is hard and is said to 
get brackish in dry seasons, but it was fresh in May, 1908, after a 
long period of deficient rainfall. It is also said to be affected by 
high tides. Wells about 4 feet deep in the beach ridges of Lostmans, 
Panther, and Pavilion keys yield fresh or only slightly brackish 
water, but deeper ones have always yielded salt water and all become 
brackish in extremely dry weather. The deepest hole reported is 
less than 50 feet deep. 

Numerous natural wells and a few shallow dug wells along the main 
line of the keys south of the Bay of Florida from Key Largo to Key 
West yield water which, though brackish except after heavy rains, is 
used by the crews of fishing boats and by the few dwellers on the 
keys. The best water tested by the writer was from a natural well 
belonging to W. H. Knowles, on Big Pine Key. Its chlorine content 
was 400 parts per million. Most of the shallow weUs at Key West 
yield water of poor quality, more or less brackish and as a rule 
liable to pollution. 

All deep drilled weUs along the keys have yielded salt water from 
about sea level to over 2,000 feet, the greatest depth reached. 

The city of Key West has no public supply of drinking water. 
The water from the deep well drilled in 1895 was formerly used for 
sprinkling the streets and fighting fires, but the mains are now sup- 
plied with sea water from a pumping plant at the navy yard. Nearly 
everybody uses cistern water for drinking and cooking. Large cis- 



372 



GEOLOGY AND GROUND WATEKS OF FLOEIDA. 



terns have been constructed at the navy yard and the United States 
Military Reservation and private dwellings are similarly equipped. 
Three plants in the city sell distUled water manufactured from ocean 
or well water. 

On the southern coast of the mainland and on the west coast keys 
in Monroe County there is little chance of finding fresh water by 
drilling. The hard limestones underlying the surface marls are un- 
doubtedly underlain at no great depth by marls and sands filled with 
brackish or salt water. Drilling through these marls and sands is 
likely to prove difficult and expensive, and the saltness of the water 
from the deep well at Marco offers no hope for fresh water at points 
along the shores of the Gulf or of the Bay of Florida. Enough work 
has been done on the keys south of the bay to show how slight is the 
chance of getting potable supplies from deep wells. This is particu- 
larly true of Key West, where remoteness from the mainland and 
especially from any region elevated enough to supply water under 
pressure sufficient to carry it under the Bay of Florida, and the salt- 
ness of the water found by the wells already sunk, indicate that 
deep drilling will prove futile. 

Typical wells of Monroe County. 



Location. 


Owner. 


Driller. 


Date 
sunk. 


Depth. 


Diameter. 


BigPinfeKey 


Florida East Coast 
do 


Rv 




1909 
1908 


Feet. 
711 
687 
500 

2,398J 
960+ 
700 
534 
700 


Inches. 

4 


Indian Key Channel 




H.Walker 


4 


Key West 






Do 


City. 
Otis . 






1895 
1909 
1909 
1907 
1908 


8 


Do 


rnhnsnn 








Knights Key 


Florida East Coast Rv 




6 


Marathon 


.do 






6 


Do 


do 




6 












B 




Head- 


Depth 

to 
roci:. 


Qual- 
ity of 
water. 


Surface for- 
mation. 


Type of 
well. 




Location. 


IB 


i 

<! 


Remarks. 


Big Pine Key 


Ft. 
711 
652 


Ft. 


Ft. 




Ft. 
-9' 


Feet. 
700 


Pn.lt 


Pleistocene.. 
Recent. . 


Drilled.. 
...do 


Not used 


TndiaTi KeyChannpl . , 




dn 


Do. 


Key West 






Pleistocen 
. . .do... 


^ 




Do 
















Salt 




Drilled.. 


Do. 


Do 










.do 




Knights Key 


700± 












Salt 


-do... . 


Drilled., 
dn 


Abandoned. 


Marathon 












-5 
-5 





do 


do 

do 




Do 




rln 


c 


lo 


Dn. 



















GEOLOGY AND GEOUND WATERS OF FLORIDA. 378 

NASSAU COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Nassau County comprises a tract of moderate elevation in the 
extreme northeast corner of Florida, between St. Marys River and 
the ocean. A large part of its surface is flat and rises only a few 
feet above sea level. This lowland area represents a broad terrace 
formed beneath the sea; most of its surface is less than 25 feet above 
sea level. 

Near the western edge of the county a tract of higher land, with 
an altitude of 40 to 60 feet, represents another terrace. A third 
terrace, still farther inland, is 70 to 100 feet in altitude and forms a 
relatively narrow plain extending northward from the south line of 
the county. 

Several streams of moderate size head in the county and flow 
either to St. Marys River or directly to the ocean. 

Sink-hole topography, such as characterizes the lake region in the 
central part of the peninsula, is notably lacking in Nassau County. 
Some broad tracts of poor drainage form more or less extensive 
swamps, the largest being in the northwest. The county includes 
a large island (Amelia), which is separated from the mainland by a 
narrow sound known as Amelia River. 

GEOLOGY. 

Gray Pleistocene sand thinly mantles the surface of the county 
and more or less completely obscures the underlying formations. 
Beneath the Pleistocene sands are red and yellow sands and sandy 
clays, which have been correlated with the Lafayette (?) formation 
farther westward. These sands and sandy clays are referred tenta- 
tively to the PUocene, but the absence of fossils makes their correla- 
tion more or less uncertain. At intervals along St. Marys River in 
the western part of the county dense gray limestone, marly clays, 
and some sand of uncertain age are exposed. 

The Hawthorn formation and the Vicksburgian limestones are 
deeply buried by younger formations, but they doubtless underlie 
the entire county at a depth of a few hundred feet. 

In thickness the Pleistocene sands are generally thin, in few places 
exceeding 20 to 25 feet. The underlying red and yellow sands may 
reach a thickness of 20 to 30 feet, and the limestones, sands, and 
clays of the Jacksonville and Hawthorn formations probably attain 
a maximum thickness of over 500 feet. However, but little definite 
information concerning the thickness of any of the subsurface forma- 
tions can be obtained. The Vicksburgian limestones are known to 



374 GEOLOGY AND GROUND WATERS OF FLORIDA. 

attain a thickness of several hundred feet in the counties to the 
south and they are probably equally thick in Nassau County. 

Log of city waterworks well at Fernandina. 



Thickness. 


Depth. 


Feet. 


Feet. 


120 


120 


5 


125 


10 


135 


50 


185 


215 


400 


112 


512 


5 


517 


27 


544 


22 


566 


167 


733 



Sand and shale. 
Rock 



Sand 

Clay 

Green clay 

Rock 

Blue clay 

Rock (with shark's teeth) 

Shell and "coral" rock, water-bearing; flow 28,000 gallons per hour. 



WATER SUPPLY. 

Source. — The Pleistocene and Pliocene sands of Nassau County 
supply large quantities of water at a moderate depth. The Jackson- 
ville formation furnishes more or less water at varying depths, but 
the supplies are seldom utilized because they do not have sufficient 
head to furnish flows except possibly on very low ground. The 
Vicksburgian Hmestones are the best water-bearing rocks and they 
supply a large quantity of water for flowing wells at numerous 
points on the lower terraces. The exact height to which the water 
will rise has not been determined but is probably at least 50 to 60 
feet above sea level. 

Quality. — The water from the Pleistocene and Pliocene sands is 
soft and is usually regarded as satisfactory for all general purposes. 
The deeper supplies are all hard and most of them contain hydrogen 
sulphide. Very deep wells in this county, like the deepest wells in 
Jacksonville, would doubtless find salt water. 

Development. — ^Most of the water used for ordinary domestic and 
farm purposes is obtained from wells 5 to 30 feet in depth. 

One of the city wells at Fernandina, only 110 feet deep, probably 
draws its water supply from the Jacksonville formation. All the other 
deep wells reported in the county appear to obtain water from the 
Vicksburgian limestones and the supplies are usually large. Good 
flows can be obtained except on some of the high land in the western 
part of the county. 

Both Callahan and Fernandina have public water supplies from 
deep wells. At Callahan water is obtained from a single well about 
600 feet in depth and 3 inches in diameter; there is no pumping 
plant, the pressure being supplied by the artesian head. At Fernan- 
dina two wells, 731 to 733 feet deep, supply a large system with 
water ample for all purposes. 

No large springs are reported from Nassau County, but small ones 
are numerous. 



NASSAU COUNTY. 
Typical wells of Nassau County. 



375 



Nearest 

town or 

post office. 


Direction 
and dis- 
tance. 


Owner. 


Driller. 


Date 
sunk. 


Surface 
formation. 


Geologic 
source. 


Type of 
well. 


Use. 


Bryceville 




Mrs. G. M. 


Stafford. . . 
...do 


1905 

1904 

1903 
1905 

1888 

1907 
1888 

1897 


Pleisto- 
cene. 

...do 

...do 


Vicks- 
burgian 
1 i m e - 
stone. 

...do 

...do...... 




Domestic. 


Callahan... 
Do 


Center.... 


Bri 

Citize 

Town 
City. 


3e. 
ns... 


Bored and 

drilled. 
Drilled.... 
...do 

...do 

...do 

do 


Public 
supply. 
Do. 




h mile east. 
...do 

...do 

§ mile 
n r t fa- 
west. 

1 mile east. 






...do 

...do 

...do 

do 


Jacks n - 
ville for- 
mation. 

Vicks- 
burgian 
1 i m e - 
stone. 

...do 

do 


Boilers. 


Do 

Do 

Do 


...do 

...do 

Fernan- 


Partridge . 
Walker.... 


Public 
supply. 

Do. 

Drinking 
and ves- 
sels. 

Ice factory 
and soil- 
ing dis- 
tilled 
water. 


Do. 


dina 
Dock & 
Real t y 
Co. 
J. W. Sim- 
mons. 




...do 


...do 


...do 






Nearest 

town or 

post office. 


4 

1 


1 


a 
o 




03 «- S 

OJ GQ 


Depth to 
principal 
supply. 


Quality 
of water. 


Yield per 
minute. 


Remarks. 


Bryceville.. 
Callahan... 


Feet. 
650 
400 
400± 

110 

731 
733 

600+ 
762 


In. 
6 
3 
3 

3 

8 
10,8,6 

6,8 
4 


Feet. 


Feet. 
8( 


Feet. 

+ 

40 

+354- 

-11 

+ 15± 

+ 15± 

+i5+ 


Feet. 


Sulphur. 


Gallons. 
Few. 
75-100 
Many. 

Many. 

...do 

...do 

Many. 








Do 

Fernandina 

Do 

Do 

Do 

Do 


70 
110 

■■'450 
"■456 


2( 

a3C 

a 25 
02s 

a4 
23 


1st flow 
190. 

no 

"isr"flow 
500±. 

'lst^flow556,' 
gradual 
increase 
below. 


Sulphur. 

...do 

...do 

...do.... 

...do 

...do 


From cavernous rock; 
does not affect bcilers. 

Forms hard scale. 

Reported to become mud- 
dy before astorm; forms 
hard scale in boilers. 

16 pounds pressure; 
forms hard scale in 
boilers. 



a Estimated. 
General water supplies in Nassau County. 





Topographic 
location. 


Source of water. 


Surface forma- 
tion. 


Shallow wells. 


Town. 


Depth. 


Supply. 


Principal water 
beds. 


Callahan . 


- 
Plain 


Public and shallow 

wells; cisterns. 
Pubhc supply, 

shallow wells; 

deep wells and 

cisterns. 


Pleistocene 

do 


Feet. 
10-30 

5-20 


Moderate 

Ample 


" Pftnin<?nla.r " 


Fernan- 
dina. 


Low sand 
dunes. 


limestone. 
Do. 



376 



GEOLOGY AND GKOUND WATEKS OF FLOEIDA. 



General water supplies in Nassau County — Continued, 





Deep wells. 


Thickness 
of sand. 


Depth to 
water. 


Increase or 

decrease of 

supply. 




Town. 


Depth. 


Supply. 


Head above 

sea. 


Sewerage system. 


Callahan . 

Fern a n - 

dina. 


Feet. 
600± 
730-760 


Large 

...do 


Feet. 
35+ 


Feet. 
30 
120 


Feet. 
5± 


None 

...do 


None. 

Discharges i n t < 
river. 



ORANGE COUNTT. 

By G. C. Matson. 
GENERAL FEATURES. 

Orange County occupies a large area near tlie eastern border of the 
peninsula. It lies partly in the lake region and extends eastward to 
St. Johns Eiv^er, where a belt of lowland forms a broad terrace. This 
terrace is less than 25 feet above sea level and rises abruptly to a more 
extensive plain 40 to 60 feet above the sea. Toward the west 
another terrace rises to a height of 70 to 100 feet, and this terrace is 
bordered by the elevated lands in the central and western portions 
of the county. The upland rises to over 100 feet above the ocean 
and is marked by numerous depressions occupied by lakes. The 
largest of these bodies of water — ^Ijake Apopka — ^lies partly in. Lake 
County. Small lakes are numerous in the central part of the county 
and extensive swamps occur farther eastward. 

A large depression near Orlando formerly drained through an open 
sink. A few years ago the opening became clogged and the de- 
pression filled with water, submerging a portion of a suburb known 
as Jonestown. It finally became necessary to sink wells to drain 
the depression, and according to Sellards ^ five of these wells are still 
in operation. Four of them are near the original sink, where they 
reach an underground channel at a depth of 140 feet, and the fifth is 
one-half mile west of the sink, where porous rock was encountered 
at 340 feet. 

GEOLOGY. 

The surface deposits of Orange County consist of gray Pleistocene 
sand, underlain by yellow sands and sandy clays derived from the 
weathering of the subjacent rocks. The northwestern part of the 
county is covered by the limestones, clays, and sands of the Alum 
Bluff and Hawthorn formations. Near the northwest corner of the 
county the. Hawthorn formation is thin, but it thickens toward 
the southeast, where it dips beneath younger beds. The surface 
sands in the southern and southeastern parts of the county conceal 

1 Sellards, E.H., Preliminary report on the underground water supply of central Florida: Bull. Florida 
State Geol. Survey No. 1, 1908, p. 63. 



OBANGE COUNTY. 377 

the older formations, but the presence of Pleistocene, Pliocene, and 
Miocene shell marls in the wells at Kissimmee suggests that these 
beds are probably represented in eastern and southern Orange 
County; however, satisfactory exposures or well samples are lacking. 
The Vicksburgian limestones underlie the entire county and may reach 
the surface at some localities northwest of Orlando. They are 
buried beneath the younger formations toward the eastern edge of 
the county. 

The thickness of the surficial sands is in few places great. The 
Pleistocene gray sand probably averages less than 25 feet, except near 
the southern edge of the county, where it is much thicker. The 
yellow residual sands are commonly less than 20 feet thick. The 
thickness of the Alum Bluff and the Hawthorn formations is in few 
places great, but the underlying Vicksburgian Hmestones probably 
have a total thickness of several hundred feet. 

WATER SUPPLY. 

Source. — ^In Orange County the Pleistocene gray sand and the 
residual sands and clays form an important source of water for shal- 
low wells. Deeper wells commonly penetrate the Vicksburgian 
limestones, though in some localities they stop short of these beds 
and in such places they obtain water from porous rocks belonging 
to the Alum Bluff or Hawthorn formations. In the southeastern 
parts of the county the Pliocene and Miocene beds may be valuable 
aquifers, but as yet that region has not been settled, and their water 
value has not been determined. 

Quality. — ^The surficial deposits furnish an abundance of soft water. 
The deep water beds, especially those in the Vicksburgian limestones, 
furnish hard water that may contain sulphur and, in the deepest beds, 
doubtless does contain salt. However, the Vicksburgian limestones 
furnish the best water in the county because they are free from 
danger of contamination by polluted surface drainage except where 
impure water is permitted to enter the ground through open sinks 
or drainage wells. 

Development. — Shallow wells, ranging in depth from 7 to 40 feet, 
are uniformly successful in this county. The water level is in few 
places more than 8 to 15 feet from the surface, but in the vicinity of 
Lake Mary and elsewhere on high ground it is from 20 to 35 feet deep. 

The deep wells range in depth from 65 to 550 feet, but they are 
commonly from 100 to 200 feet. They obtain large supplies, and in 
St. Johns Valley the head is sufficient to give flows on ground less 
than about 20 feet above the river. Good flows are reported from 
wells near Lakes Monroe and Jessup. The area near Lake Monroe 
contains several hundred wells, in or near the city of Sanford, most 
of which are used for subirrigation of market gardens, a purpose for 
which the water is admirably adapted because it has a uniform 



378 



GEOLOGY AND GEOUND WATERS OF FLORIDA. 



I 



temperature, whicli promotes the growth of the vegetables and pre- 
vents their being harmed by sHght frosts. The large demands on 
the artesian beds at this locality may lower the head and diminish 
the quantity of water, but as yet no change has been noted. Out- 
side St. Johns Valley the head of the water brings it so near to the 
surface that it can be pumped with ease, and hence irrigation is 
extensively practiced. In some localities shallow wells supply water 
for irrigation, and the yield of such wells is often large. 

There are some excellent springs in Orange County, though but few 
of them are used. In the largest, Wekiva Spring or Clay Spring, 
located 5 miles northeast of Apopka, the water emerges in a basin 
about 30 feet in depth and forms a good-sized stream tributary to 
St. Johns River. The spring is owned by Judge W. S. Bullock. A 
hotel and a bathhouse have been built at the spring. The water, 
which is from the Vicksburgian limestone, is hard and contains some 
sulphur. Its temperature is about 75° F. The flow is constant and 
the water is not muddy after rains. (See PI. XVII, B, p. 234.) A 
number of other large springs exist in this part of the county. At 
Altamonte Springs a small spring is used to supply a hotel. 

Sanford and Orlando have public water supplies that are regarded 
as satisfactory; at each the water is taken from a lake, though Sanford 
has an auxiliary supply from wells. The lake water is soft, but the 
wells at Sanford furnish a hard sulphur water, a fact which probably 
accounts for the use of the lake water. 

General water resources of Orange County. 





Topographic 
location. 


Source of water. 


Surface 
forma- 
tion. 


Shallow wells. 


Town. 


Depth. 


Supply. 


Quality 
of 

water. 


Principal 
water beds. 


Apopka. 


Plain 

Ridge. 

Plain 

do 

do 

Gently undu- 
lating plain 
Plain....... 


Driven and dug 

wells. 
Driven wells 


Pleisto- 
cene. 
...do 


Feet. 
10-40 

12-20 
7-15 

21-40 
15-35 
20-30 

12-20 

10-35 

15-25 

12-35 

17-25 

&-15 
19-37 
14-27 


Ample,. 

...do.... 
Good.... 

...do.... 
Ample.. 
Moderate 

Ample.. 


Soft... 

...do.. 
...do.. 

...do.. 
...do... 
...do.. 

...do.. 


"Peninsular" 


Port Reed 


limestone. 
Do. 


Goldsboro. 

Lake Mary 

Longwood 

Maitland 

Ocoee 


Drilled and driven 

wells. 
do 

Driven wells 

Driven and two 

drilled wells. 
Driven and dug 

wells. 
Driven and drilled 

wells. 
Public supply and 

driven wells. 
Dug and drilled 

wells. 
Drilled weUs, public 

supply; driven 

Driven" and drilled 

wells. 
Driven and drillerl 

wells. 
Driven wells 


...do.... 

...do.... 
...do.... 
...do.... 

...do.... 

...do.... 

...do.... 

...do.... 

...do.... 

...do.... 
...do..-. 
...do.... 


Do. 

Do. 
Do. 
Do. 

Do. 


Orlando 




Do 


Plain 

Gentle slope- 
Plain 

do 

Gently undu- 

latiQg plain 

Plain 




Good.. 
Soft... 
...do.. 

...do.. 
...do.. 
...do.. 


Do. 


Oviedo 




Do. 


Sanford... 


Ample.. 

Good.... 
Moderate 
Ample.. 


Do. 


Spears Grove.... 
Winter Park.... 
Winter Garden.. 


Do. 
Do. 
Do. 







. ^^„_,:,^«„ o'7n 


125 
125± 


Sulphvir 


70 
90 
90 


Many. 




do 




Several. 






148 














98 

i 

200 
80 

L 


180 

160 

90 

40 
100 

88 
150 

135 
130 

150 

160 
136 
132 


do 

do 

Hard, sulphur 


100 


150 

130± 

100 
Several. 
Several. 

Several. 
Several. 

60 
Many. 

Several. 




Very slight sulphur . . 






Sulphur 

do 

do 

do 

do 

do 


40 

40 
70 

75 
50-80 

70 


Probably3 wells. 






Hard 


40 
40 


Many. 
Many, 

Many. 

Many. 
Several. 
Several. 

Many. 




do 

Sulphur 


^ 


"qo 


145 
145 

"'"i29" 

1 


do 

do 

do 

do 

Hard, sulphur . 


90 
90 
90 
60 


Probably several wells. 































..... 


150 
































































Typical shallow well. 




150 






Many. 






















































































j 


















c Estimate 


d. 







Typical wells of Orange County. 



Longwo 
MaitlaiK 



M. K. Fletcher 

Judd (Park 



House). 
Denter Tuipen 
rt'm. Oglesby. 



J.R. Pound 

City 

Dale's Faini 

Dr. .T. N. 5I:ifElroy. 
II. W. Mi'lr.lf 



. C, Brya 
. L. Cusli 



G. U. Calhoun 

Chas. Campbell 

Virginia D. Campbell 



ity w 

. F. Chappell " 

. E. Criggm — 



G. H. Fernald a 

Florida Land i 

ODization Co.o 

Mrs. Grange — 



. F. Connell. 
. W. Tilden.. 



Comstock 

n. F.Foley... 
D. B. Hunter.. 



Garrett Bros... 
D. W. Dillard.. 



(;. J. MuCulley 

G.lt. Fernald A Co.. 



W. A. Stadord 

G. H. remold &Co.. 
F. W. Mahoney 



A. E. Hall 

:::!do!:;::::::::: 

O. H. Fernald * C 



O.n.Fornald&Co.. 



Geologic source. 



Vicksburgian lime- 



Vicksburgian lime- 



Domestic and Irriga- 







Ued.... 


Irrigation::::::::::::' 




do 

Drinking and irriga- 


led.... 


Drlnking 




Not used 




Sjff,?i?i°'.r.^.^."!v.: 


»••"■■" 


braiiiagu' and' sewa.ge 
Factory no longer in 

operation. 
Cooling condensers.... 




iiraLii age anil' sewage:: 



Locomotives 

Bottling works 

Domestic and irriga- 

Doinestic, manufac- 
turing, irrigation. 

Pnblic supply 

Irrigation, etc 

Drinking and domos- 

..:.(io 

Drinking and irrjga- 

Irrigat'ion, etc 

Irrigation 

Irrigation 



165± 
; 100-160 



Igo-K 



First now ai w (Oct. 



Many. 
Many. 



Sulphur, strong 

Sulphur and salt.... 

Sulphur 



Hard, sulphur 

Very slight sulphur. 
Sulphur 



Hard... 

....do.. 
Sulphui 



60-60 6100 -20 



Probably several welK 



JWi"— wapaio-i; 



o Water. 
! page 378.) 



Supply Paper V. S, Geol. Survey I 



Q'TO 



OSCEOLA COUNTY. 

General water resources of Orange County — Continued. 



379 





Deep wells. 


Aver- 

tMck- 
ness of 
sand. 


Depth 
to water. 


Sewerage 
system. 




Town. 


Depth. 


Supply. 


Head 
above sea. 


QuaUty 
of water. 


Remarks. 




Feet. 




Feet. 




Feet. 

5 

5± 

15 

1 

12-18 

Few. 


Feet. 

Several. 

8-12 

6-10 

20-35 

12-30 

35 


None.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 




Fort Reed . . . 














70-125 


Large 




Sulphur. 




Lake Mary. 




















Maitland 


150-250 


Large 


-35 






Oakland 




Conditions simi- 


Ocoee 


200 

150-500 
200-500 
80-240 
75-160 








Few. 
35+ 


Several. 

6-10 

Several, 

2-20 

4-5 

6-10 

20 

Several. 


None . . . 

...do.... 
...do.... 
...do.... 

Small... 

None . . . 

...do 

...do.... 


lar to those at 
Winter Gar- 
den; some flow- 
ing wells near. 
200-foot well 


Orlando 

Do 


Large 

Moderate.. 

Large 

...do 


-40 

Several. 

-5-20 

41± 


Sulphur. 
Hard.... 


abandoned 
because it did 
not flow. 


Oviedo 


Sulphur. 
...do 


20-40 

is' 

Few. 
7-12 




Sanford 

Spears Grove.. 




Winter Park... 


150-200 
150± 


Large 

Ample 


-20 
-30 






Winter Garden 




Flowing wells on 
shore of lake 1 
mile east. 







OSCEOLA COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Osceola County lies between St. Johns and Kissimmee rivers and 
extends from Lake Okechobee northward nearly 75 miles. The 
surface includes three broad terraces, which are believed to represent 
former levels of the sea. The lowermost of these terraces is from 20 
to 40 feet above sea level and extends from Lake Okechobee a short 
distance northward. In the eastern part of the county this terrace 
probably appears in the St. Johns Valley. The second terrace has 
an altitude of 40 to 60 feet, and a third is represented by the broad 
plain upon which the town of Kissimmee is located. The upper ter- 
race has an altitude of 70 to 100 feet above sea level, and the north- 
western corner of the county probably rises above the level of this 
terrace. 

Lake Okechobee and several of the smaller lakes occupy depressions 
in the sand which forms the lowermost terrace. Similar depres- 
sions in the upper terrace have given rise to lakes, among them being 
Lake Tohopekaliga and several smaller lakes. All the terraces con- 
tain numerous broad denressions occupied by swamps. 

GEOLOGY. 

The surface deposit of Osceola County consists of gray sand of 
iPleistocene age. Locally recent deposits of peat and muck occupy 



380 GEOLOGY AND GROUND WATEES OF FLORIDA. 

depressions in the sand. In the hammocks near Kissimmee River 
Eldridge found fragments of Hmestone containing fresh-water shells 
believed to be of Pleistocene age. In discussing the Pleistocene and 
Pliocene geology reference was made (p. 141) to fossils collected from 
wells near Kissimmee. The fossils indicated that the beds at a depth 
of 96 feet were Pleistocene and that those at 150 feet were Pliocene. 
The Miocene marl is believed to be present beneath the Pliocene. 
The Hawthorn formation has not been identified with certainty in 
any of the wells, but it probably underlies the county and is in turn 
underlain by Vicksburgian limestones. 

Little definite information can be obtained concerning the thickness 
of the different geologic formations in Osceola County. One aston- 
ishing fact is the great thickness of the Pleistocene sands and shell 
marls. At Kissimmee, for example, these deposits are at least 96 
feet thick, and the maximum may be considerably greater. At Kis- 
simmee the 300-foot well of Franz Agnew is believed to have reached 
the Vicksburgian limestones, though this statement is merely 
tentative. 

WATER SUPPLY. 

Source. — The Pleistocene sands are water-bearing in Osceola County 
and in many places furnish good supplies within a few feet of the 
surface. Both Pliocene and Miocene sands and marls probably yield 
abundant water, and some of the flows south of Kissimmee are be- 
lieved to be furnished by these formations. Nothing is known con- 
cerning the water capacity of the Hawthorn formation, but the 
Vicksburgian limestones should furnish abundance, with sufficient 
head to give good flows on low ground. 

Quality. — The water from the Pleistocene sand is soft. The beds 
of Pliocene and Miocene age and the Vicksburgian limestones furnish 
water which is moderately hard and is usually salty. 

Development. — ^At Kissimmee wells at 4 to 15 feet deep obtain 
water, and good supplies could probably be obtained in all parts of 
the county within 40 or 50 feet of the surface. Several deep wells are 
less than 150 feet in depth, and only a few wells exceed 300 feet. 
Good flows can be obtained where the surface does not rise more than 
72 feet above sea level, and in some places flows have been obtained 
on slightly higher ground. 

Although no attempts have been made to procure flowing water 
near the southern end of the county, there is little doubt that flows 
could be obtained. The water, however, might be too saline for use. 
This is inferred from the fact that the salinity appears to increase 
toward the south, the wells south of Kissimmee containing much more 
salt than those at the town. 



Nearest town 
or post office. 



Campbell . . 

Do 

Kissimmee. 



Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 



Do. 
Do- 
Do. 
Do. 
Do. 

Do. 

Do. 
Do- 

Do. 

Do. 

Do. 

Do. 

Do. 
Do. 

Do. 
Do. 
Do. 



Do. 
Do. 
Do. 

Lanier . 



Xareoossee. 
Do 



Do. 



leva- 
ion 
30ve 
;ea. 



Veet. 



65 



6 65 
6 65 



6 65 



6 65 
C55 
6 65 



6 72 



|675 

65 
65 
67 



67 

6 60 

20 

C70 



Head 
above 

or 
below 
surface. 



Feet. 
+ 2 
- 4 



- 1- 

- 5 



+ 4 

- 2 

+ 1 
H- 1- 
+ 4 

- 1 
+ 1 

+ 1 

+ 

+ 
+ 
+ 

+ 

+ 



- n 

- n 

+ i 

+ 3 

+ 4 

+ 3+ 

+ 3+ 

+ 3+ 

+ 1 



+ 

-27 



Depth 
to rock. 



Feet. 



145 



Depth 
to prin- 
cipal 
supply. 



Feet. 

130 

150 



96 



120 



100 
140 
140 



120 
140 



160+ 



210+ 
200+ 
120" 



Mineral character of 
water. 



Sulphur. 
do.. 



Sulphur. 

do.. 

do.. 



Sulphur 

do 

Sulphur, slight salt. 

Sulphur, slight 

Sulphur 

Sulphur, slight salt. 



do.. 

do.. 

do.. 

Sulphur. 
do.. 



Sulphur, slight salt. 

do 

do 



do.. 

do.. 

Sulphur. 
do.. 



.do. 



Depth 

to 
second 
sup- 
plies. 



Feet. 



8+ 



10 
40-100 



10+ 
10+ 



162 



290 



Yield per 
minute. 



Gallons. 

90. 

Few. 
Several. 
15 and 16. 
Few. 
Several. 

Many. 
Few. 
Few. 
Many. 

Many. 
Many. 

Many. 
Many. 
Many. 

Many. 

Many. 
Many. 

Many. 

Few. 

Several. 

Several. 

Several. 
Several. 

Many. 
Many. 
Many. 

Many. 
Many. 
Several. 
Many. 

Several. 
Several. 

Several. 



7685! 



Typical vmUs of Osceola County. 



Nearost town 
orpostoillce. 


Direction and dis- 


Owner. 


Driller. 


Date 
sunk. 


Surface forma- 
tion. 


Oeologic source. 


^'S.°' 


Use. 


Depth. 


Diame- 


Casing 


Eleva- 


Head 
above 

betow 


t?rk 


Depth 
supply 


Mineral Character Of 
water. 


Depth 
second 


"ili^! 


f'T" 


;mne north 














Boiler and domestic... 


Feet. 

Ill 
300 

196 
11 
285 

97 

97 
349 

0.5 
70 

210 
160 
006 

Si 

187 
412 

400 
262 

41.? 
200± 


Incha. 
11 


Feel. 


Feet. 


Feet. 
+ 2 


Feel. 
90 


Feel. 
130 




Feet. 


Oallons. 


























2 mUes southeast.. 








Pleistocene.... 


Vicksburgian lime- 
stone? 


Drilled.... 


Domestic and irriga- 
Domestic and stock... 


P 

1 

? 

1.1 

11 
6 

4 

ij" 

4 

n 
a' 


Ill 
132 

140 


6 05 
6 65 










S.H.BuUock 


Fr kB 


1901 

1898 
1907 


- P 




120 




8+ 






"4m,le.Vomh 


J^ohn Anderson........ 


:::::do:::::::: 


Miocene 






Several. 




H.-FiemSg-.:::::;;:: 

Cap^.H. Clay Johnson 


do.? 


S^"" 


do 


















1.70 
665 


+ 1 + 

+ 

+ 3^- 

-27 
-13 


""iis 


100 
140 
140 




















40-100 














IcG manufacturing 

•brirSdng' 














Pleistocene.... 

:::::do:::::::: 




Drilled.... 

:::::do::::: 


"m" 

140 


6 65 










Kissimmeo Lumlier Co 
Lee Parsons Catt'te Co.. 


John Anderson 

■c.'b.°NeWYaiids'.".:;"' 


"1907" 


:::::do:::::::::::::::: 

Pleistocene 




120 


Sulphur; sliiht 


10-t- 








Domestic and stock... 






Se.«,T.27S.,R. 






Do 












do 




Many. 




do 






























Do 










:::::do:?::::::::::::::: 

Pleistocene 

do 














...do 




Many. 
































s!eR%s R 

■sec:''277TV27S.;' 
s|-|,\27S.. 
Sec.' 30, T. 27 S., 

415- ^^^- 

do 

Smiles south 

}mUo southwest.. 

2 miles north 


do 

do 

do 

do 


'.'/^]al'///.'.V..'.'.''.'.'.'. 

do 




do 

do 

:::::t:::::: 


do 

do 

do 

do 


do 

do 

:::::uS:::::::::::::::: 
do 










do 

























:::::d2::::::::::::::: 




Many. 


















Do 










do 




Few. 


Do 

Do 

g°:::::::: 
B2::;:::- 

Do 

.-li:::;: 

N'arcoossoe 

Do ; 

Do 


W.A. McCool 

Moon & Adams Celery 

G.F.Parker 

"sehoo°idistrioV.;.;;;: 

Atlantic Coast Line. . 
G.W. Hopkins" 

l.-^.-iSioT::::::: 

United Land Co 


do 

do 

N.F.Bass 

'N.'c.BrymV.v.:::::! 

do 

■Anderson:.'::::".:;!: 

C. O.Newlands 

do 


"igos" 
im 

1906 


do 

do 

:::::do::::::: 

;;;;;£;;;;:: 

Ploistoceno... 
do 

do 


Vicksbuigian lime- 

...*.X: 

do 

Vi'c'ks'bu'rgian iimo- 

:::■-&■:::::::::::::: 

' Vi'e'ks'bi'i'rgian' ' ' lime'-' 


do 

do 

do 

do.... 

do 

:::::do:'.'.': 
.°.'.X::: 


do 

Domestic and stock... 

'toi'gatio'i;::::::::::::: 
iS*-:::::::::: 

Drinking 

Drinking and stock... 

11*;;::::::::::: 

Domestic and slock.... 
do 










do 




Several. 


m+ 

150 

"■iio"' 

200 
"296"' 


6 72 

6 75 
65 
67 

4 










Several. 


""90 


160-H 
"2i6+' 


do 

Sulphur, slight salt.... 

::::do::::::::: 

....do 

....do 

....do 


162 
'296'" 


Several: 

s 
s. 

Many. 
Several. 

Several. 



Water-Supply Paper U. i 



PALM BEACH COUNTY. 

General water resources of Osceola County. 



381 





Topo- 
graphic 
location. 


Source of 
water. 


Surface for- 
mation. 


Shallow wells. 


Town. 


Depth. 


Supply. 


Quality of 
water. 


Principal 
water beds. 


Kissimmee. . . 
Narcoossee 


Plain 

do.... 


Driven and 
drilled 
wells. 

do.... 


Pleistocene.. 
do 


Feet. 
4-10 

20-35 


Ample 

do.... 


Soft 

do.... 


"Peninsnlar" 
limestone. 

Do. 









Town. 



Deep wells. 



Depth. 



Supply. 



Head 
(above 



Quality of water. 



Average 
thick- 
ness 

of sand. 


Depth to 
water. 


Feet. 

3-10-H 

30± 


Feet. 
-3-8 
8-10 



Remarks. 



Kissimmee. . , 
Narcoossee . . 



Feet. 
80-487 
2004- 



Large. . 
..do... 



Feet. 
70± 
70± 



Sulphur; some salt 
Sulphur 



No sewerage system. 
Do. 



PALM BEACH COUNTY. 

By Samuel Sanford. 
GENERAL FEATUKES. 

Palm Beach County lies north of Dade County, its northern bound- 
ary extends to the north end of Lake Okechobee, and it includes 
within its borders a large section of the Everglades and most of the 
Allai)attah Flats. In the southern part of the county the Everglades 
extend almost to the ocean shore; farther north the expanse of 
relatively dry land is much wider, but there are few settlements more 
than 10 miles from the railway along the coast. The average eleva- 
tion of the surface is under 25 f eet^ the highest points being in the dune 
ridges west of Hobe Sound. Loxahatchee, Jupiter, and Hillsboro 
rivers are the principal streams flowing from the Everglades. 

GEOLOGY. 

Most of the islands or barrier beaches along the coast have coquina 
outcropping or lying below the Recent beach sands. Peaty deposits 
and marl lie in the swamps about the sounds back of the beaches. 
Gray sands mantle the country between the coast and the prairies along 
the Everglades. Inland the sands in places, notably west of Gomez, 
contain considerable clay. The Pahn Beach limestone outcrops in 
a few places near the eastern margin of the Everglades and extends 
westward under them an unknown distance. AU the above deposits 
are of Pleistocene age. The exact thickness of the Pliocene, Miocene, 
and upper Oligocene deposits is undetermined, and little is known of 
their structure. The samples from the Palm Beach well (p. 168) give 
the only recorded information regarding the depth to the Vicksburgian 
limestone at any point in the county. The average southeastward 
slope of the top of the limestone from near its outcrop in Pasco 
County to Palm Beach is apparently about 5 J feet to the mile, but 



382 GEOLOGY AND GEOUND WATEES OF FLOEIDA. 

that the top of the limestone maintains a uniform dip is very doubtful. 
The meager information obtained regarding the deep wells in the 
cattle ranges west of the Everglades in Lee County indicates that the 
top of the limestone is warped and is not a plane of even slope. The 
depth to the limestone at any point in the county except Palm Beach 
and its immediate vicinity can not be predicted from the data 
available, but it is everywhere hundreds of feet below the surface. 

WATER SUPPLY. 

Source. — Sands, sandy marls, coquina, and limestones, all classed 
as Pleistocene, are the important sources of underground supply. 
The Vicksburgian limestone is tapped by a few wells in the northern 
half of the county. 

There are a few springs of no particular importance along the shores 
of lagoons. Most are of small flow. 

Details of the deep flowing wells near Gomez, Hobe Sound, and 
Palm Beach are given in the table on page 384. The log of the Palm 
Beach well appears on page 168. This well and the well east of 
Hobe Sound are of some interest, as they were sunk on islands. The 
wells are so deep and the bodies of water separating the islands 
from the mainland are so narrow that the island location does not 
determine the quality of the water. The water from the well near 
Gomez, a mile inland, was highly mineralized, according to report. 

Driven or bored wells 10 to 125 feet deep yield waters that differ 
with the location, depth, and character of the water bed. 

Two wells on Loxahatchee River are of more than average depth. 
One 2 miles west of West Jupiter found salt water; the driller, W. O. 
Weybrecht, of West Palm Beach, gave the following log: 
Log of well of W. Dim/mock, 2 miles west of West Jupiter. 



Thickness. Depth. 



Sand; with hardpan at 31 to 32 feet 

Rock, rather soft, white; many shells; a few streaks of hard rock. 



Feet. 
40 
61 



Feet. 
40 
101 



Another well at an orange grove 4 miles farther west yields good, 
though slightly sulphureted water. The driller reported the follow- 
ing section: 

Record of well of Leinhart & Dimmock, 6 miles west of West Jupiter. 



Thickness. 


Depth. 


Feet. 


Feet. 


4.5 


4.5 


2 


6.5 


37.5 


44 


4 


48 


3 


51 


3 


64 


4 


58 


2.5 


60.5 



Sand, hard, dark gray 

Shells, in hard bed ^ 

Mud, soft, white or grayish, plastic 

Sand, hard, grayish; like beach sand 

Limestone, soft, white 

Shells; with very hard, dark rock li feet thick 

Sand, soft, dark gray, clayey 

Limestone, rather hard, dark gray; water at 51 to 58| feet. 



PALM BEACH COUNTY. 



383 



The shell bed at 4 J feet yielded numerous well-preserved marine 
shells of living species. 

A dug and driven well 65 feet deep on top of the dune ridge back 
of Hobe Sound station yields excellent water. 

In the vicinity of Palm Beach and West Palm Beach are many 
shallow wells and a number 50 feet or more deep. Those at West 
Palm Beach are reported to show decided differences in depth to 
rock at points a short distance apart. One of several at the ice plant 
shows the following succession, according to the driller: 

Record of well at ice plant, West Palm Beach. 



Sand, hard, gray 

Quicksand, with reddish sand at 28-30 feet 
Sandrock 




Three water-bearing beds are reported at West Palm Beach within 
100 feet of surface. The above well tapped the second. Most 
driven wells go to the first at about 10 feet. 

A mile west of West Palm Beach the Model Land Co. sunk two wells 
in search of a possible supply for the city and for Palm Beach. The 
wells were not developed. The following log is compiled from the 
notes of the driller, H. Walker, and from samples. The sands are 
siliceous. 



Record of No. 2 well of Model Land Co., a mile west of West Palm Beach. 



Sand, fine to medium, yellowish 

Sand, and marine shells (shell marl) 

Sand, with hard nodules and shell fragments 

Limestone, hard, grayish; with shells 

Limestone, hard gray, fossiliferous 

Beach sand, full of marine shells 

Coquina, soft, yellowish (worn shell fragments with sand) 

Sand and gravel (sand and fine gravel with worn shell fragments and bits of calcite) . 

Sand, medium, gray (many hard nodules and worn shell fragments) 

Sand, fine, white (contains leached shell fBagments and bits of calcite) 

Limestone, hard, gray (bits of shells as above and fine sandy limestone) 

Sand, loose; water bed. 



Thickness. 


Depth. 


Feet. 


Feet. 


25 


25 


5 


30 


17 


47 


2 


49 


6 


55 


15 


70 


4 


74 


10 


84 


6 


90 


4 


94 


4 


98 



South of West Palm Beach few wells call for special mention, the 
great majority being under 20 feet deep. The driller, E. T. King, 
furnished the following record of one near H3rpoluxo: 



Record of well of Andrew Garnett, 2 miles west of Hypoluxo. 






Thickness. 


Depth. 


Sand, yellow, surface 


Feet. 
6 
32 
24 


Feet. 
6 


Sand, white 


38 


Corininfi,; frflsh Wflter at fi2 fft^t 


72 







76854°— wsp 319—13 25 



384 GEOLOGY AND GROUND WATERS OF FLORIDA. 

The same driller furnishes the following log of a well near Delray: 

Record of well of 0. Eleasen, west of Delray. 




Depth, 



Sands, surface 

Coquina ^ 

Quicksand 

Coquina, of early Pleistocene age; fresh water at 119 feet. 



Feet. 
40 
43 
108 
119 



Few wells in Delray are over 20 feet deep. A canning factory gets 
a sufficient supply of water from a 4-inch well about 30 feet deep. 

Artesian prospects. — ^The yield and quality of water obtainable near 
the coast by deep drilling has been demonstrated at Palm Beach, Hobe 
Sound, and Gomez. There is every reason to believe that the deep 
water is more strongly mineralized south of West Palm Beach. 
Better water can be had toward Lake Okechobee. As in Dade 
County, the most promising sources of supply are the sands, marls, 
limestone, and shell beds from 50 to about 150 feet below surface. 
Good water that will not rise above the surface can be obtained in 
many places by wells 5 to 20 feet deep in the surficial sands and 
limestones. On coastal islands and in places on the mainland near the 
shore wells may yield salty or brackish water from a few to several 
hundred feet below sea level. 

Typical wells of Palm Beach County. 



Nearest town 
or post office. 


Direction 
and dis- 
tance. 


Owner. 


Driller. 


Date 
simk. 


Surface 
forma- 
tion. 


Geologic 
source. 


Type of 
well. 


Use. 


Delray 


Near.... 


Delray Can- 
ning Co. 

0. Eleasen.... 

Indian River 
Land Assoc. 






Pleisto- 
cene. 

..do 


Pleisto- 
cene, 

Pleisto- 
cene(?) 

Vicks- 
burgian 
lime- 
stone, 
do 


Drilled.. 


"Rnilpr pqti- 


Do 


E.T.King 




ning veg- 
etables 
andfruit. 

T)nm*>stip 


Gomez 


J mile 

east. 

2 miles 
east. 

3 miles 
north- 
east. 

2 miles 
west. 

1 mile 
north. 

2 miles 
north- 
west. 

1 mile 
north. 

6 miles 
west. 

2 miles 
west. 

1 mile 
west. 




do ., 






Do 






...do... 






Hobe Sound. 

Hypoluxo 

Pahn Beach. . 


T.A.Snyder.. 

Andrew Gar- 

nett. 
C.LCragin.... 


E.T.King 




...do 

...do 

...do.... 


...do 

Pleisto- 
cene. 

Vicks- 
burgian 
lime- 
stone. 


Drilled.. 

...do 

...do.... 


Irrigation. 

Domestic. 
Irrigation. 


Do 


Munyon 

C.LCragin... 


W.O.Wey. 
brecht. 


1899 




Do 










West Jupiter. 
Do 


Leinhart & 

Dimmock. 
W. Pennock. . 

Model Land 
Co. (2 weUs). 


W.O.Wey- 

brecht. 
...do 

H. Walker 


1908 

1903 

1906 
1905 


Pleisto- 
cene. 


Pleisto- 
cene. 


Drilled.. 


Domestic. 


West Palm 
Beach. 


Pleisto- 
cene. 


Pleisto- 
cene. 


DrUled.. 





PASCO COUNTY. 



385 





Typical wells of Palm Beach County — Continued. 






1 


1 

s 


1 


1 

|i 
1 


Head— 


o 

1 


r 


Quality 
of water. 




Nearest town 
or post office. 






Remarks. 


Delray 

Do 


Feet. 

30 

119 

1,200 

900+ 
1, 100+ 

62 
1,212 

125 
1,300+ 
59J 

60 
/ 99 
i 87 


In. 
3 


Feet. 


Feet. 


Feet. 


Feet. 


i?'eg<. 


Feet. 


Fresh... 
Fresh... 
Saline... 
do 


Yield large. 














Gomez 


4 








Flows. 

+ 
Flows. 






Not used. 


Do 












Do. 


Hobe Sound... 






20 








...do 




Hypoluxo 

Palm Beach... 

Do 


2 

4 

2 




. 32 
2 


"'i,"2i2" 


Fresh... 

Saline 
sul- 
phur. 

Salt 




1,000 


4 
5 


38 


34 


Yields 250 gallons 
per minute. 

Not used. 


Do 




+ 
-2 




West Jupiter. . 
Do 


2 
2 

} « 


67 


8 


6 


57 


57 


Hard, 

fresh. 

Salt 

} Fresh... 




West Palm 
Beach. 


i 30 


}X5 




1 


47 
40 


99 

87 


/Not used; yield 
\ large. 




I 



PASCO COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Pasco County is on the west coast of the penmsula. The western 
part of the county is a broad plain rising from 20 to 25 feet above sea 
level, and this plain is bordered by successive terraces ranging in 
altitude from 40 to 60 and from 70 to 100 feet. The relief of these 
plains is very slight, but farther inland the surface becomes gently 
rolling with smoothly rounded hills and basin-shaped depressions. 
This topography results from the collapse of the roofs of underground 
channels forming sink holes. In many localities the depressions are 
occupied by ponds or lakes, but in Pasco County most of the sink 
holes are dry. The only important surface streams in the county are 
Pithlachascotee and Hillsboro rivers, and neither of these drains a 
large area. Anclote River drains the extreme southwestern corner 
of the county. 

GEOLOGY. 

The surface materials of Pasco County consist of gray sands under- 
lain by red and yellow sands contauiing in some localities a slight 
proportion of clay. The surficial deposits are underlain by limestones 
of Oligocene age. In the eastern part of Pasco County the limestones 
of the Tampa and Hawthorn formations lie near the surface. The 
Vicksburgian limestones are near the surface in the western part of 
the county, but farther east they are partly covered by the younger 
limestones. 

The thickness of the surficial deposits is in few places great, and 
exposures of the underlying limestones are not uncommon. The 
Hawthorn and Tampa formations are commonly thin, though near 



386 



GEOLOGY AND GROUND WATERS OF FLORIDA. 



the southeast corner of the county the limestones and clays of the 
Tampa formation attain a maximum thickness of perhaps over 100 
feet. The Vicksburgian limestones should have a thickness of several 
hundred feet, but there are no well records to prove it. 

WATER SUPPLY. 

Source. — ^The surficial sands commonly furnish an ample supply of 
water for shallow wells, and the Tampa formation may also yield 
some water at moderate depths, but the best water-bearing formations 
of the county are the Vicksburgian limestones. In the western part 
of the county and in some localities in the eastern part the Vicks- 
burgian limestones may be penetrated by wells less than 100 feet in 
depth. 

Quality. — The surficial sands furnish soft water, but nearly all the 
deeper wells yield hard water. 

Development. — On low ground few shallow wells of Pasco County 
exceed 30 feet in depth and many of them are not over 10 feet. The 
water level is near the surface, and hence suction pumps are commonly 
used. The supplies obtained by these wells are large enough to meet 
all the ordinary domestic requirements. Many deep wells go down 
less than 100 feet, though a few go considerably deeper. All the 
water from the deep wells is hard but is generally considered satisfac- 
tory. These wells will supply large quantities of water, and hence 
they are utilized for industrial purposes. Very deep wells may yield 
highly mineralized water, and as there is little or no probability of 
their giving flows there is no incentive to drill to great depths. 
Typical wells of Pasco County. 



Nearest town 
or post office. 


Direction and 
distance. 


Owner. 


Driller. 


Date 
sunk. 


Type. 


Use. 


Depth. 


Dade City 

Do 


Near 


City 


W. A. Spark- 
man. 

do 

do 

T. J, Zimmer- 
man. 
J.D.Allen.... 

do 


1905 

1906 
1907 

1904 
1904 


Driven. . 

...do.... 
Drilled.. 

...do.... 

...do.... 

...do.... 


PubUc 

No water.... 
Ice manu- 
facturing. 
Sawmill 

...do 

...do 

Turpentine 

still. 
Sawmill...... 

...do 



Turpentine 
still sup- 

, ply- . 

Locomotives 
Domestic . . . 
General 


Feet. 
53 


IJ miles north. 
J mile south- 
east. 
Near 


HenrvCray... 

Muller& Zins- 
ser. 

Gulf Cypress 
Co. 

Aripeka saw- 
mill. 
do 

Rice&Phelpso 

Gulf Pine Co.. 

S. S. Goffin. . . 
The Spencer 

well. 
Stubbs Bros. 

&Co. 

Atlantic Coast 

Line. 
Dr. J. F. Cor- 

rigan. 
Convent 

J, S. Flanagan. 

Atlantic Coast 
Line. 


74 


Do 


45 


Ehren 


150? 


Fivay 

Do 

Herndon 


do 

do 

1 mile south... 

Near 


120 

96 
120 


Odessa 


T. J. Zimmer- 
man. 

.....do 

N.C.Bryant.. 

J.D.Allen.... 

do 

Owner 

T. J. Zimmer- 
man. 

W. A. Spark- 
man. 

W.A.J.Pres- 
cott. 


1907 

1902 
1894 

1906 

1898 
1900 
1906 
1906 
1907 


Drilled.. 

...do.... 
...do 

...do.... 

...do.... 
...do.... 
...do.... 
...do.... 
...do.... 


104 


Pasco 

Pasadena 

Port Richey.... 
Richland 


do 

do 

4 miles north. . 
Near 


270 
6300 

147 
90 


St. Leo 

San Antonio 

Do 


do 

do 

5 miles south- 
north. 
Near . . . . 


75 
98 
85 


Trilby. ..... . 


Locomotives 31 











a Water-Supply Paper U. S. Geol. Survey No. 102, p. 250. 



b Estimated. 



PINELLAS COUNTY. 

Typical wells of Pasco County — Continued. 



387 





1 


1 





Head— 


2 

1 


n 


Pro- 
tecting 
clays 
pres- 
ent. 


Q,uality of 
water. 




Nearest town or 
post office. 


i 
1 

< 


g 


Yield 

per 

minute. 


Dade City 

Do 


Inches. 
2 
2 
6 
3 
8 
8 
2 

4 
3 
8 
6 
8 
3 
2 
2 
10 


Feet. 
50 
55 
45 

■ ■ ■ '40' ■ 
40 


Feet. 


Feet. 


Feet. 
30-35 


Feet. 


Feet. 
50 


Yes... 


Hard 


Gallons. 










Do . 


88 
90 


73-71 


15-17 




45 


"Yes."!' 


Hard 

...do... . 


100 


Ehren 




Fivav 




8 

6 

50 

11 

30 

86 . 

14 

30 

32 

25? 

8 

5 








...do 




Do 












...do 




Herndon a 






120 






Soft, min- 
eral. 
Hard 


Many. 


Odessa 


35 
270 
170 

30 
....... 

98? 
82 
19 


6 57 

no 


6 46 
80 






Pasco 


""'iso' 


270 


Yes... 


..do 




Pasadena 


...do 




PortRichey 






147 


No 


do ... 




Richland 


6 93 
191 


63 
159 




...do 




St. Leo 


69 


73 
98? 

85 


Yes... 


...do 

...do 




San Antonio 




Do 






Yes 


do 




TrUby 


59 


54 




...do 



















a Water-Supply Paper U. S. Geol. Survey IS 0. 102, p. 250. 



General water resources of Pasco County. 



6 Estimated. 



Town. 


Topographic 
location. 


Source of water. 


Surface 
formation. 


Shallow wells. 


Depth. 


Supply. 


Dade City 


Rolling 

Level 


Wells 


Clays 


Feet. 

10-35 


Fair. 


Hudson 


Wells and cistern 

Wells 






Lacoochee 


Rolling 

do 


do 


10-30 


Fair. 


Pasco 


do 


Clays 


Do. 


Richland 


do 


do 


Some clavs 




Do 


San Antonio . . . 


Hilly 


do 


Clays 






St. Leo 

TrUby 


do 

Level 


do 

do 


do 

do 




Fair. 

















Shallow wells. 


Deep wells. 


Sewerage 
system. 


Town. 


Quality of 
water. 


Principal 
water beds. 


Depth. 


Supply. 


Quality of 
water. 


Dade City 

Hudson . . 


Some soft 


Limestone 

do 


Feet. 
157 


Abundant 

do 


Hard 

do 


None. 
Do 


Lacoochee 




do 


90 
270 

90 
165 

75 

85 


do 


do . 


Do. 


Pasco 




do 


do 


do 


Do 


Richland 




do 


do 


do . 


Do. 


San Antonio . . . 




do 


do 


do 


Do. 


St. Leo 




do 


do 


do 


Do. 


Trilby . . 




do 


do 


do 


Do 
















PINELLAS COUNTY. 



Pinellas County was recently formed from a portion of Hillsborough 
County. Its wells have already been described. (See pp. 319-325.) 



388 GEOI.OGY AND GEOUND WATERS OF FLORIDA. 

POLK COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Polk County is in the south-central portion of the peninsula. The 
surface ranges in altitude from less than 70 feet to more than 200 feet 
above sea level. The marine terrace which is well developed at 
Kissimmee extends into the eastern and southern parts of the county. 
There are also narrow terraces along Peace River and the other large 
streams. East of Bartow some areas rise over 150 feet above sea 
level and similar upland tracts occur in the western and northern 
parts of the county. At Lakeland a narrow ridge rises to an altitude 
of over 200 feet. 

Lakes are numerous on the terrace in the eastern and southern 
parts of the county, where they occupy depressions in the sand. 
On the upland some of the many lakes appear to be due to depressions 
in the surface sands; but others occupy sink holes formed by the solu- 
tion of the underlying limestones. 

GEOLOGY. 

The surface of Polk County is mantled with gray sand, which ^ 
obscures the underlying formations, except where it has been removed 
by erosion or by artificial means. Beneath this sand at some localities 
lie deposits of land-pebble phosphates — Bone Valley gravel. The 
Bone Valley gravel is best developed from near Lakeland southward 
beyond Bartow; extensive areas of it lie west of Bartow and smaller j 
tracts northeast and south of the town. Marls of Pliocene and Mio- ^ 
cene age probably extend into the eastern part of the county; but 
their existence can be inferred only from their occurrence in Osceola 
County. Limestone belonging to the Hawthorn formation ( ?) was en- 
countered in one of the phosphate mines near Bartow, and the forma- 
tion possibly underlies the county. The Vicksburgian Umestones 
are reached in all the deep-drilled wells and they extend beneath the 
entire county but are so deeply buried that they are only known from 
well records. 

The thickness of the several geologic formations in Polk County 
has been only approximately determined. In the western part of 
the county the gray sands average less than 10 feet, but near the 
eastern boundary they attain a maximum thickness of perhaps 
over 100 feet. In some places the Bone Valley gravel is over 30 feet 
thick, but it probably averages about 20 feet. The PHocene and Mo- 
cene marls, are thought to underlie the eastern portion of the county, 
but no information is available as to their thickness. The thickness 
of the Hawthorn formation and the Vicksburgian limestones is un- 
certain, but it probably amounts to several hundred feet. 



POLK COUNTY. 389 

Log of the well of Smith d: Marshall, at Arcadia. 



Thickness. 



Depth. 



No samples 

Sand, light brown 

Same; but containing shell fragments 

Sand, gray 

Limestone, light gray 

Sand, dark gray 

Limestone, light gray 

No samples 

Limestone, mixed light and dark gray 

Limestone, light gray ; fragments of dark-colored chert . 

Limestone, light gray 

Limestone, dense, light gray 

Limestone, light gray; fragments of darker chert 

Limestone, hard, dark brown 

Limestone, granular, light brown 

Limestone, dark brown; some chert 

Limestone, fine grained, gray 

Limestone, light gray 

No samples 

Limestone, very fine grained, light gray 

Limestone, porous, white 



Feet. 





Feet. 


10 


10 


10 


20 


20 


40 


20 


60 


20 


80 


20 


100 


20 


120 


10 


130 


20 


150 


20 


170 


20 


190 


20 


210 


10 


220 


30 


250 


20 


270 


20 


290 


20 


310 


10 


320 


10 


330 


20 


350 


20 


370 



This well doubtless penetrates some distance into Vicksburgian 
limestone, but the exact depth to these rocks is uncertain. 

WATER SUPPLY. 

Source. — ^The surficial sands are the source of an abundant supply 
of water throughout the county. Locally the Bone Valley gravel 
may yield water, but it is not regarded as an important water- 
bearing formation. The Hawthorn formation may also supply 
water, but it is difficult to determine whether the water comes from 
this formation or from the underlyiag Vicksburgian limestones. The 
limestones of Vicksburg age are the most important water-bearing 
rocks of the county and supply large quantities for deep-drilled wells. 

Quality. ^-The surficial sands furnish soft water, but all the older 
geologic formations yield hard water. 

Development. — Shallow wells* range in depth from 15 to 30 feet and 
obtaia an abundance of water in all the settled portions of the county. 
Some wells have been driven for 60 to 80 feet, but good water is gen- 
erally found near the surface. 

At Carters Mill several wells 50 feet or less in depth, obtain flowing 
water, and in the vicinity of Loughman many good supplies are 
obtained at 80 to 100 feet. The water at these localities contains a 
slight amount of sulphur but is unusually free from other mineral matter. 
Wells on low ground near Nichols and Mulberry also obtain flows, 
but the head is not sufficient to yield flows on the upland in the west- 
ern part of the county. On the low ground near Kissunmee Kiver in 
the eastern part of the county flowing wells similar to those in Osceola 
County could probably be drilled. In Polk County deep wells have 
been drilled by several of the phosphate companies and all of them 



390 



GEOLOGY AND GBOUND WATEKS OF FLORIDA. 



have obtained large quantities of water, which rises within easy pump- 
ing distance of the surface. These wells penetrate the Vicksburgian 
limestones and indicate the character of the water which may be 
obtained from these formations throughout the western half of the 
county. Near the eastern edge of the county much of the deep water 
is likely to contain salt and some of it may be too saline for use. 
Bartow, Lakeland, and Mulberry each have public supplies obtained 
from wells. The water is hard, but it is satisfactory for all general 
purposes and the supplies are reported to be ample. 

General water resources of Polk County. 



Town. 



Topo- 
graphic 
location. 



Source of water. 



Surface 
formation. 



Shallow wells. 



Depth. 



Supply. 



Quality 
of water. 



Principal 
water beds. 



Auburn- 
dale. 
Bartow..,. 



Car ters 
Mill. 

Eagle Lake 

Green Bay. 
Lakeland . . 



Loughman. 
Mulberry . . 



Rolling 
Plain.. 



Plain 
along 
creek. 

Plain . . . 

...do.... 
...do.... 



...do. 
...do. 



Driven and drilled 
wells. 

Public supply; 
driven and 
drilled wells. 

Driven wells 



Pleistocene 

sand. 
....do. 



.do. 



Pierce. 



Winter 
Haven. 



..do. 
..do. 



Driven and drilled 

wells. 
do 

Public supply; 
driven and 
drilled wells. 

Driven and drilled 
wells. 

Public supply; 
driven and 
drilled wells. 

Driven and drilled 
wells. 

do 



.do. 



Feet. 
25-85 



50-60 



35-60 



25^5 



15-25 
30-45 



28-50 
15-25 

20-30 
25-80 



Ample.. 
..do 



Soft. 



.do.... 



..do Hard, soft, 

j and some 
i sulphur. 

..do....! Soft 



"Peninsular" 
limestone. 
Do. 



Do. 



.do 

.do 



..ao 

-.do.... 

..do.... 
..do.... 



.do 

.do 



..do. 
..do. 



.do- 
.do. 



Do. 



Do. 
Do. 



Do. 
Do. 

Do. 
Do. 



Town. 



Deep wells. 



Depth. 



Supply. 



Head 

(above 

sea). 



Quality 
of water. 



Aver- 
age 
thick- 
ness of 



Depth to 
water. 



Sewer- 
age 
sys- 



Remarks. 



Auburn- 
dale. 

Bartow. . . . 

Carters 
Mill. 

Eagle Lake 

Green Bay . 

Lakeland . . 

Loughman. 

Mulberry . . 

Pierce 

Winter 
Haven. 



Feet. 



Feet. 
12± 



125-720 
200 (?) 



Large. 
...do.. 



2+ 



Hard. 
...do.. 



Feet. 
14± 



8-25 



None 



...do.. 
...do.. 



336-400+ 
116-126 



150 



Large . 



100-125 



Hard... 
..do... 



Large . . 



..do. 



75 
35 

40 ± 
4-8 
lOdb 



22-43 

10-15 

23 

8± 

15 
1.5-25 
20-30 



...do. 
...do. 
...do. 
...do. 

...do. 
...do. 
...do. 



South of town in swamp; 
several flowing wells. 





1 














ipth 
clc. 


Depth to prin- 
cipal supply. 


Quality of water. 


Depth 
to sec- 
ond 
sup- 
plies. 


Yield per 
minute. 


Remarks. 


T 


r- 


Feet. 


Hard 


Feet. 


Gallons. 
SOO 
400 

500 








720 
Near bottom. 


Sulphur, slight 








Sulphur 




1 Do. 










T 


... 


1 






550 
80+ 










do 






P 




279 




200 ± 




















800 










Sulphur 












. ..do 








C 


:;:: 


50 
132 


Sulphur, slight 




Few. 
Several. 
Several. 

Several. 
Many. 




E 


Hard 






F 


Sulphur 












do 












do 












do 




Defective casing caused aban- 
donment during drilling. 

Phosphate prospector's bor- 
ing on low ground; only 
flow in this locality. 




















Hard 






Ji 






Sulphur 






Many. 


lost at 150, but filled again! 














E 










250 

Few. 
200+ 

200+ 

Many. 
Few. 

Few. 
Few. 




IJ 






Soft 








.... 


485 


Hard 








.do 






iJ 














.... 


115 

110 
100 


Sulphur, slight 

do 


10-50 

10-50 
10-50 






do 




k 




Not completed. 


M 




121 




152 


75 
Several. 

Many. 

Many. 

500+ 












145 
145 


Sulphur, slight 

do 


25+ 
25+ 










do 




Do. 








do ... 






Do. 


N 


























No. 1 mine. 














No. 2 mine; 4 wells, 1 flowing. 
Town well. 








Sulphur . 






P 




700- 
700- 


do 


600 ± 

eoo 


600 

1,000 

175+ 






do 




P 


do 




P 






do 








500 


800 
165 

165 
165 
165 


do « 




650-700 




T 


Hard 


45 

45 
45 
45 






...do 








do 








do 






V 


do 


Many. 

Many. 

Many. 
Many. 






















Hard 








\ 


200 

1 




20+ 




A 







Wometer. 



Typical wells of Polk County. 



5 miles northwest . 



Dominion Phosphate 



T.R. Starke 

Tighlman Phospha 
Co. 



Carter's Mill Co , 

School District 

Charleston Mining & 
Manufacturing Co. 



International Phos- 
phate Co. 
Pitlmetto Phosphate 



Lakeland Refrigerator 



Carter & W. 

Everglades 



Ua Phosphate Co 
Dudley 



Hughes Specialty 
WeU Drilling Co. 

....do 

J. R. Vaughan 



Pleistocene.. 
Vicksburgian 



....doCO--- 

Pleistocene.. 



PleistoceneC?),- 

-..dof?) 

....dol?) 

Vickshurgianlir 



:ffl:: 



Phosphate minhig and 
Condensers 



Cooling coi 

Mill, holler 
Drinliing.. 



Public supply 

....do 

Phosphate mining 



Phosphate mining ai 

----do^'- 

Phosphate mining. . 

Phosphate mining. 



Domestic and stock. 
Domestio and stock . 



-wsp 319-13. (To face r 



tter-SuppIy Paper U. S. Geol. Survey No 



Sulphur, slight . 
•bottom. Sulphur 



f^uipjmr.. 

SuIplui'rV 
Hani.... 
Sulphur.. 



Hard 

Sulphur.. 



d 200 

r 



Sulphur, slight . 
Sulphur 



Hard.. 
'.'.'.'.do'.' 



Forms soate in boilors. 



""€. 



..™.. 


'■'iTSi 


....... 


■'"o^m" 


i 


■''■'ii^y: 


"'26+' 


S: 



GEOLOGY AND GROUND WATERS OF FLORIDA, 391 

PUTNAM COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Putnam County occupies an area in the northern part of the penin- 
sula, stretching from St. Johns River westward into the lake region. 
The lowland near the river forms a terrace that rises 20 to 25 feet 
above the stream and is bordered on the west by an abrupt scarp. 
Above this low plain is a second terrace several miles wide and 40 to 
60 feet in altitude. Between the second terrace and the upland is a 
third, with an altitude 70 to 100 feet above sea level and a breadth, in 
its widest part, of several miles. The upland is a portion of the 
lake region and is characterized by broad depressions occupied by 
lakes. Locally these depressions are numerous and some of them are 
large. Many of them have no surface outlet, the drainage escaping 
to underground channels which are apparently numerous and many 
of which are doubtless large. 

GEOLOGY. 

The terraces of Putnam County are covered by thin deposits of 
gray sand representing the Pleistocene. In the southern part of the 
county, near St. Johns River, the Pleistocene sands are underlain 
by shell marls of Pliocene age (Nashua marl), the exact extent of 
which is not known but which may underlie a large part of the lower 
terrace. Beneath the gray sands of the upland is a clayey sand and 
gravel. The clay is separated from the sand by washing and is used 
for the manufacture of pottery. A portion of the county bordering 
St. Johns River may be underlain by Miocene shell marls (Choctaw- 
ha tehee marl), but little is known concerning the existence of this 
marl in Putnam County. 

The Alum Bluff and the Hawthorn formations probably lie near 
the surface over a large portion of Putnam County. Beneath them 
are the Vicksburgian limestones, which may possibly reach the surface 
in some of the depressions near the western part of the county. For 
the most part, however, the Pleistocene sands effectually conceal all 
the older formations. 

The gray sands of Pleistocene age are generally thin, probably 
averaging less than 25 feet, though in St. Johns River Valley they 
may attain a thickness considerably greater. The average thickness 
of the Pliocene marl is probably less than 25 feet and the Miocene, if 
present, may not be much thicker than the Pliocene. The Alum 
Bluff and the Hawthorn formations doubtless cap the high hills of 
the western portion of the county, though they may be absent in 
some of the depressions. They thicken toward the eastern edge of 
the county, where they dip beneath the younger beds. It is doubtful 



392 



GEOLOGY AKD GROUND WATERS OE ELOBIDA. 



if these formations are much more than 225 feet thick in the eastern 
part of the county and they thin abruptly toward the west. The 
Vicksburgian limestones should have a thickness of several hundred 
feet in Putnam County. 

Few important well logs could be obtained, and none of the weUs 
were deep. 

Log of well drilled in bottom of the cistern at the city waterworks at PalatTca. 




Depth. 



Sand, containing shells 
Sand 

Clay, hard yellow 



Feet. 



Log of Mrs. Mullholland' s well at Palatka. 




Depth. 



Sand 

Rock, hard. 
Clay, white. 
Clay, blue.. 
Rock, hard. 



Feet. 
85 
90 
110 

185 



Log of well at Interlachen. 





Thickness. 


Depth. 


Sand 


Feet. 
10 
12 
40 
14 
8 


Feet. 
10 


Gravel 

Clay, blue; containing kaolia 


22 
62 


Clay, red 


76 


Sanastone 


84 







WATER SUPPLY. 



Source. — In Putnam County a large quantity of water is obtained 
from the Pleistocene and Pliocene deposits. The Hawthorn for- 
mation is also an important source of water supply for wells of 
moderate depth. But the best water-bearing beds are the Vicks- 
burgian limestones, which, owiQg to their porous character, supply 
an abundance of water for drilled wells of small diameter and mod- 
erate depth. The head is sufficient to give good flowing wells on 
low ground near St. Johns River. 

Quality. — The water of the Pleistocene and PHocene formations 
is soft and is satisfactory for ordiaary uses. The presence in many 
localities of a layer of hard rock above the water-beariag sands 
serves to protect the shallow wells from pollution by impure surface 
water. Most of the water obtained in the Alum Bluff and the Haw- 



Nearj 

PQove 
be- 

)W 

face 



Bostwi^^- 

Dol 

Dot--- 
Crescendo 
Do- - - 
Do,+- 

%+ 
''\± 

Doj6± 

16+ 
Edgar j6± 

FlorahC 
Hunter 2 

Huntin, 
Interlao2 
Do> 

Padgett 
Palatka^ 

DojS 
Do.4 



Doj 
Do^-- 

D0J13 
Do]3 

DoJ 
Doj2 

Doh 

Do,-. 

Doj- 

Do.. 

Do> 

Do.-- 

Do.-- 

Do.- 

Do> 

Do.-- 

Do.O 



Do. 
Doj-- 

D„.| 

Peniel., 

Do.+ 
Rice Cr(- - 
Rodmai+ 
Do.- 
San Mat- 
Do. -- 
2 
Do. 
f- 
Do. 

6 

Do. 

Seville. 2 

8 

Do. 

2 

WelakaJ 



Do.i 
WoodbdSi 
1 



Depth 

to 
rock. 



Feet. 



68 



60 



57 
"i95 



130 



230 



224 



80 



Depth 
to prin- 
cipal 
supply. 



Feet. 



248 



300 



65 



100+ 



190 
"236+ 



183 ± 
250 



Quality of water. 



Sulphur. 
do.. 



Soft. 



.do. 



do... 

Sulphiu:. 

Soft 



do. 

Hard.. 



Soft. 



Hard, sulphur. 



Soft 

Hard, sulphur. 



Sulphur. 



Hard, sulphur. 
Chalybeate . . . 



180 

'is?' 



Sulph;ar . 
do.. 



.do. 
.do. 
.do. 
.do, 



302 



230 
227 



Sulphur. 
do.. 



200+ 

"i75+ 



320 



280 



160,309 
'"'2i8"" 



Sulphm-. 

do.. 

do.. 



Sulphur 

Hard, sulphur. 



Hard, sulphur. 



do.. 

Sulphur. 



Sulphur. 



Yield per 
minute. 



Gallons. 



Several 



Few 
Few 
Few 



Few 
Few 



Few 



Few.. 
Many. 



Several 



Many. 



Many. 



Many. 
Many. 



Many. 



125 



Few . 



300 



Many. 
Many. 



Several . . 



300 
Several . . . 



Many. 
Few.. 



Many. 



Remarks. 



First flow 30-50 feet. 
Do. 
Do. 



First flow 30-50 feet. 
Do. 

Do. 

Do. 
Flows in kaolin pit but does 

not rise to surface. Forms 

scale in boilers. 
Rises nearly to surface. 



Second supply at 60 feet. 
Drilled in 60-foot sink. 
Eight wells. 



Second supply at 50 ± feet. 



Too much iron for washing 
satisfactorily. 



Two wells. 



Well not yet completed. 



Some additional supplies. 



Forms scale. 
Do. 



Affected by weather; water 
corrodes metal. 



The deeper supply highly 
mineralized. 

Flows from 175 feet. 



c By barometer. 



Typical ii'cUs of Putmim. Co 



























above 


Head- 






1 






""-^i^s- 


Direction and 
distance 


0\VTier. 


Driller. 


sunk. 


Surface 
formation. 


Geologic source. 


^Wl.°' 


Use. 


Depth. 


"ci™" 


Casing 


Above 


iF 


Depth 


*?fpa'l'" Qriality Of water. 


^^Ztr 


Remarks. 






























suriMe 




supply 








I,„,t„fck 




O.N. Glisson* Co... 


H. Merrill 


1905.. 


Pleistocen...... 


V/^Jb;;^rgian 


Drilled... 


Turpentine still, public 
Tmpentijie still. 


Feet. 
235 


Indies. 


Feet. 
60+ 


Feet. 


Feet. 


~^. 


Feet. 


Feet. 




Oallom. 




Do 

Do 


3 miles southeast. 


G.^K^Giiion::::::::: 


do 


"isos" 


:::::dc 




do 

do 


...do 


230 

dIp^. 




00+ 






+ 












Do 




'jirs'. .^rbVecht'estatj:: 


:::::do:::::::::::::::: 


1905.. 


:::::do 




do 


:::do::::: 

...do 


D'rinkiiig'andstocii:'.".'. 


3 




"ifeV. 




"'026" 


"'^ 


"2-i8' 


'^e:es. 


"smmiV. 






SSStJparkesiate: 




'isss:: 


■-•-;^° 










100+ 
100+ 
Shal- 
low. 






Few: 




+ 16+ 












Do 




Mrs. Lyon 






do 








bWestYc.v:::::::::: 












'sii'ti:::::::::::::::::: 


'Few'::::: 


First flow 30-50 feet. 


Do 




J. W. Miller estate-... 






do 






do 






Few. 




+ 16± 






do 


Few 


Do. 


ES;:;::;;:;:::: 

Do 




■mto&baVh::: :::::: 

W.C.Norton 

F.W.Payson 






do 

do 






Pui)iic"supplV"and 

S:::::::::::::: 


30°ol 
40± 


1 5 




Few. 




+ 16+ 
+26 




"'366' 


do 

Sulphur 

.^"■k';;:::::::::::: 


Few 

Few 

Few 


Do. 

First flow 30-60 feet. 
Do. 


Do 




A. B. Torrey 






do 






Domestic 


Shal- 






Few. 




+16+ 






do 


Few 


Do. 


Do 

Edgar 




id|rTS^Caoiin- 


Owner 


■1905::: 


:::::t::::::: 




Driven::: 


do 

Washing kaolin 


2 


■""i,5" 


Few. 
120 


"m 


+16± 




65 


•Ha^i"::::::::::::::: 


Few 

Many.... 


Do. 
Flows in kaolin pit but does 

not rise to surface. Forms 

scale in boilers. 
Rises nearly to surface. 


as?™!::::;:;:: 




Poweii&cov;:::::::: 


■H:Merv'in':::::::::::: 




do 


'SSi^'»"" 


Driven... 
Drilled... 


Drinking and stock... 


25 


2- 


2.5 






~+ 






Soft 


Several . . 


tereC-:;::::; 


Similes northwest. 


Marie A. Baker!. 

Edw. FirkimS. 












Iirigation, farm 


420 


4 








-12 


60 




Hard, sulphur 






^::=:. 


Tiimewest:::::::: 
Near:::::::::::::: 
•4-nuiesnorth:::::: 

do 


C. H. Heminpvav... : 

rrSrr;::::: 

-A.tlantic Coast Line... 
do 


■ii:"A:BakVr.";:::::::: 

■H:Mer;'"inV;:::::::::: 
do 


■i965;;i 


■pieiitocene:::: 


ViekibuT-giin' 
limestone. 


Driiied::: 
Driiied::: 

...do 

...do 


Domestic aiid Vtock : : : 

RaiB°shoii:::::::: 

Drinking 

do 


175 
206 

230+ 

325 


^ 


iis"^ 


"ciio' 

....... 




+15 


,57 

'" "i95 


""166+ 

"ioo' 

""236+ 


"soii:::::::::::::::::: 
"Haid^s'uiphii'r'.".::::: 
"sui'phm:::::::::::::: 
do 


•iiany';::: 
'Maiiy:::: 




Palatka 






sfiS-iSfooifsr'- 

Eight wells. 


SS::::::::::::: 

Do 

Do :: 


do 




City 




is're::: 


do 








Drmking fountain 


183 


2" 


■■"■.56± 


"Vis' 




Maty. 
+23 


::::::: 


""m± 


do 


Ui^nf. '.'.'. 


Second supply at 50 ± feet. 


ES::::::::::::: 


Near 

....do 


I'v^S^r^-::::. 












Irrigation, drinkmg... 


250 


4 




IS 






250 


Hard, sulphur 


Many 




ii. Mervin : 


iniii... 


Pleistocene.... 




Driiied:::. 


Irrigation 


















Chalj'beate 




Too much iron for washing 


D^::::::::::: 




O.M. Davis 






do 


Pleistocene 


do 


Washing 


i^ 






111- 




+2 










satisfactorily. 




J. E. Edmonston 


"iLMorvin;::::::::::: 




do 










"60+ 














ES: 

SS::-"------ 




Geo.E.'GaVv;:::::::; 

LO. Gould 

M.'D.'jaraiBo'n.:::::" 


:^..t::::::::::::::: 




:::::ao:::::::: 


limestone. 

do 

do 

do 


...do 

:::t::::: 


Livery stable 

' i3oinc,siic aiid stock : : : 


1 


^.. 




017 








''-\^]'^e::ee}. 




Two woUs. 


iSiieSorth::::;:: 


"iLMm-in;;::: : : 

n. Mervin 


'::;::i--- 


:::;:t::::::: 


:::::do:::::::::::: 


:::t::::: 

...do 


BfSe™'^'"::::: 

do 


215 


:' 


S0± 
30 


a 15 
25 




...t.. 


" "isii'r'is;""!:::::!!":::::::::::;:::: 

1 i do 


■ ""•'"'iis" 






^^^^S^::::- 




;;«- ■ ■ 


: ::dS:::::::: 


:::::dS.v:::::::::: 


:::do:::::: 




235 


....... 








v.:.::.'. 




::::::::!::::::'°:::::::::::::;:: 


"f".."w":::::: 


Well not yet completed. 




Mi.ss.Mullh6lland 






....aI'.'.'.'.V.'. 














".."is " 










--■- 






I'aliitka Icn Co.... 












Ice factory 


247 


4 








"+26" 






s.dpi;;"- I 300 






Selden Cypiess Door 

feSas.;:::-: 


BiVbce:::::::::::::::: 


:mii;::: 


:::::do:: 


Viokshurgian" 


ririiieci:::: 


Condensers 






■362" 










""302" 






£;:;;;;;;- 


Ncaf::::::::::::;: 




1911-1... 




...'.'.do!'."'"' 


...do 


Drinking 


227 


2 


230 


....... 




+25' 


"""22." 


227 





Many::::: 


Some additional supplies. 




W. A. Walton 






"Vffhh.rcTic. .. 


Vjeksliurgian' 


Driiied:::: 






1 


'ijo ■ 






+2.5 












'X 

^«_crcek::::::::: 




Uurham&l'rilclielt.. 


H. Mervin 


1902. . . 


ill. 


hmiMOTie, 


...do 


Irrigation 


Zis 




g|- 


•■30 




+2+ 




200+ 


Sulphur 


Many 






Williams ,1.. Co 


do 










Manufacturing 




















S'e'r'e'r'a'l'::: 






UticaUi-iot&TileCo. 










'iiriiied:::: 


Drinking and stock. 












■+4+"" 






....do 


Formsscale. 




Rodman Lumber Co.. 


'H:s.cummin"gs:::::: 






:::::do:::::::::::: 




Boilcni,etc 


125 




















«»|.w;:::::::: 


2 miles north:::::: 


Ge'o. H .' iWch :::::::: 




'isss'" 


:::::do:::::::: 


:::::t::::::::::: 


:::do:::::: 


Doinestic aiid stock. 


333 


,, 


■■»■■ 






- 


"""'sir 


""3ai" 


s'u'i'p'hui: :;::::: :::::.. 


Several... 




SmanP. Beach!- 












Domestic and Irriga- 




'' 




25 


- 


+ i2 


30 




Hard, sulphur 




Do 


1 mile .south 


W.L. Fuller 






Pleistocene.... 


Vickshurgian 


Drilled.... 


...".''.°: 


300 


6 




15+ 




+ 












"" 


do 


Mrs. C. A. Holton 




isot... 


,10 


..""i;;!'.''."';. 


...do 


Domestic and irriga- 


2S(, 


1, 




+ 20± 




+ii 






Hard, sulphur 




Affected by weatter; water 


sevfc:::;::::;:;. 

Do 


do 


■;uran°tic'Coasti:ine::: 




is9ll± . 


i'leistocelie.... 


Vicksbu'rginn' 


Driiied:::: 


Do'mMtlc 

Locomotives 


200± 


4 




25 




-IS 


SO 


280 


sii'i'pbur'.::::::::::::::" 


Many::::: 




8 miles east 


MeSFS Turpentine Co.. 






jl„ 


limestone. 


;]„ 


Drinking and tiupen- 


1.50± 


4 





Low. 




+ 2 






....do 


Fow 




Welakn 




Welaka Mineral Water 

Co. 
Wilson Cypress Co.... 




19011... 


do 


....,!„ 


..do 


D^taking.: 


309 


3 


110 


22 




-16 


™.309| 


....do 




^'inS^d.^""-'^ '"•^'* 


'ij"miiesnorthe^t' 






do 




...do 


Lumber camp 


96 






5 




+I6± 




-o,-J- 


sii'ipiiiii: ".'.'.:::::::::: "M^'y:.--'' 


Flows from 175 feet. 




J. E. Edihonston 


■H:MerVin\"::::::::::: 


■w6.5::: 


do 


vickViiirgian' 




Stock 






'"66" 


»35 






'" 1 




— __ 












limestone. 








1 








1 


1 





-wsp 319-13. (To face page 392.) 



. Water-supply Paper U. S. Oool. Survey No. 



PtJTKAM COUNTY. B93 

thorn formations is moderately hard. The Vicksburgian Hmestones 
supply hard water, and very deep wells in this formation would 
doubtless find strong salt water. 

Development. — Wells 10 to 30 feet in depth usually obtain good 
supplies of soft water, but a few wells have been sunk to a depth of 
40 to 50 feet. These wells are usually deemed satisfactory for all 
ordinary purposes, but safer supplies may be obtained at greater 
depths. In the vicinity of Crescent City a number of flowing wells, 
which probably obtain water from sands of Pleistocene or Pliocene 
age, have sufiicient head to raise the water about 16 feet above 
the low ground bordering the river. A deeper supply of artesian 
water, which heads about 26 feet above the surface, has been obtained 
by Miller & Cash at about 300 feet. The suppHes from the shallow 
wells are soft, but the deep well yields hard sulphur water. At 
Palatka, in the St. Johns Valley, flows are obtained from the Vicks- 
burgian limestones at slightly more than 200 feet. The exact head 
of this water has not been determined, but it is probably more than 
25 feet above the river. In the western part of the county the wells 
are aU shallow. Deep wells would penetrate the Vicksburgian 
limestones, but flows probably could not be obtained. At Edgar a 
65-foot well, with a head sufficient to raise the water within a few 
feet of the surface, discharges directly into the pit of the Edgar 
Plastic Kaolin Co. The exact source of this supply could not be 
determined, but it is probably some porous layer in the Alum Bluff 
or the Hawthorn formations. 

Small springs are numerous in Putnam County, but none of them 
are of sufficient size to be important. 

Both Crescent City and Palatka have public water suppHes. 
At Crescent City the water is obtained from wells and the supply is 
regarded as satisfactory. At Palatka the water is taken from 
springs and wells located near the western edge of the city. Some 
difficulty has been experienced in obtaining a sufficient quantity 
and for this reason several test wells have been sunk. These wells 
appear to have penetrated the PHocene beds and the supplies obtained 
were small. A much larger quantity of water, though possibly 
sulphureted, could doubtless be procured by sinking deeper weUso 



394 GEOLOGY AND GEOUND WATEKS OF FLORIDA. 

General water resources of Putnam County. 





Topographic 
location. 


Sotirce of water. 


Surface 
forma- 
tion. 


Shallow wells. 




Town. 


Depth. 


Supply. 


Qual- 
ity of 
water. 


Principal 
water bed. 


Bostwick. .. 


Plain 


Dug and drilled 

weUs. 
Dug and drilled 

and driven weUs. 
Public supply; dug 

and driven wells. 

Wells 

Dug wells 

Wells 

Dug and drilled 

wells and cisterns. 
Dug wells 


Feet. 
Pleisto- 
cene. 
...do.... 

...do.... 

...do.-.. 
...do.... 
...do.... 
...do.... 

do... 


Feet. 
13-25 

10-30 

15-50 

12-45 
15-18 
16-50 
18-50 

12-18 
28-35 
35-55 

17-30 
15-50 
25-35 

20-35 

16-24 


Good . . . 

Ample.. 

Small... 

Ample.. 
Small... 
Good... 
Ample. . 

Good 


Soft. . . 

...do.. 

Good.. 

Hard.. 
Soft. . . 
Hard.. 
Soft... 

.. do.. 


"Peninsular" 


Carraway 

Crescent City. 
Florahome... 


Gently rolling. 

do 

RoUing 

Plain 


limestone. 
Do. 

Do. 

Do. 
Do. 


Grandin 

Interlachen. . 

Johnson 


Rolling 

Gently rolling. 

RoUing 

do. . . . 


Do. 
Do. 

Do. 


Keuka 


Wells 


...do 


Do.... 

Small... 

Ample. . 
Good... 
Small... 


...do.. 
...do.. 

...do.. 
Hard.. 
Good.. 

.. do.. 


Do. 


Palatka 


Plain 


Public supply and 

drilled weUJs. 
Wells 


...do.... 
...do.... 


Do. 


Peniel 


do 


Do. 


Putnam Hall. 


Rolling 


do 


...do 


Do. 


San Mateo... 
Welaka 


Gently rolling. 
Plain 


Driven wells and 

cisterns. 
Dug and driven 

wells. 
Dug and drilled 

wells. 


...do.... 
...do.... 
...do.... 


Do. 
Do. 


Woodbum... 


Gently rolling. 


Good... 


Soft... 


Do. 





Deep wells. 


Aver- 

tS- 
ness of 
sand. 


Depth 

to 
w^ater. 


Increase 

or de- 
crease of 
supply. 




Town. 


Depth. 


Supply. 


Head 

(above 

sea). 


Quality of water. 


Seweragesys- 
tem. 


Bostwick. . 


Feet. 

247 ± 


Large 


Feet. 

+ 


Sulphur. . . . 


Feet. 
25+ 


Feet. 
12-15 
10-15 
Few. 
10-20 
12 

1 12-18 

10 
10-12 

23 
20-25 


None 

...do.... 
...do.... 
...do.... 
...do.... 

...do.... 

...do.... 
...do.... 
...do.... 


None 






Do. 


Crescent City. 
Florahome 


90 ± 


Abundant 


+ 16 


Hard . 


Several. 






Do. 


Francis 










12+ 

/2+ to 

i 8+ 

10+ 

5+ 

12-15 

5+ 


Do. 


Grandin 










Do. 


Interlachen . . 


118 








Do. 


Johnson 








Do. 


Keuka 










Do. 


Palatka 


100-250 
30 




25+ 


Hard 


Discharges in 

the river. 
None. 


Peniel 






Slight... 
None.... 
Slight... 


Putnam Hall. 




4+ 






20 
30 

Few. 

12-16 


Do 


San Mateo . . 










Do. 


Welaka 


309 
290 ± 


Large 

...do 


-16 

+ 


Hard or sulphur. 




Do. 
Do. 


Woodburn . . 


Sulphur. . 


28+ 


None.... 







ST. JOHN COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

St. John County is on the east coast, near the northern end of the 
State. It comprises a portion of the low coastal belt between the 
Atlantic Ocean and St. Johns River. The surface is flat and usually 
rises only a few feet above sea level, though locally it may have an 
altitude of nearly 50 feet. There are no large streams within the 
county, but some small creeks, a few miles long, drain the region 
near the coast. Swamps are numerous, especially during rainy sea- 
sons. The coast is bordered by low bars separated from the main- 



ST. JOHN COUNTY. 395 

land by shallow sounds; the most important, Anastasia Island, is 
situated opposite St. Augustine. Many of the bars are covered with 
sand dunes, some of which are of considerable height. 

GEOLOGY. 

The entire surface of St. John County is covered by Pleistocene 
materials consisting largely of white or gray sands. Coquina in 
small areas occurs near St. Augustine, is well exposed on Anastasia 
Island, and is also known to underlie the sands in other parts of the 
county, but exposures are rare. Marls of Pliocene age probably 
cover a part of the county, but they are known only on St. Johns 
River near the southwest corner, where the Nashua marl occurs 
along the banks of the stream. Well records at St. Augustine show 
that the Jacksonville formation is represented at that locality. The 
Vicksburgian limestones underlie the entire county, though they are 
deeply buried beneath younger rocks and their presence has been 
detected only in samples obtained in drilling wells at St. Augustine 
and vicinity. 

The average thickness of the Pleistocene saads and coquina in St. 
John County is probably somewhat more than 50 feet, and the Nashua 
marl may have an equal thickness, but in the absence of detailed 
information these estimates are to be regarded as uncertain. The 
Jacksonville formation is approximately 130 feet thick at St. Augus- 
tine, and its maximum thickness toward the northern boundary of 
the county is probably over 250 feet. No information could be 
obtained concerning the Apalachicola group in this county. The 
Vicksburgian limestones were encountered at a depth of about 224 
feet at St. Augustine and the samples obtained from the well at the 
Ponce de Leon Hotel show that it continues to a depth of more than 
1,400 feet, thus giving it a minimum thickness of over 1,175 feet. 

Log of well at Catholic cemetery, south of St. Augustine. 




Depth. 



Sand, fine-grained, pale yellow 

Sand, bluish gray, containing many scales of mica. 

Sand, dark colored; many shell fragments 

Clay, light gray; with shells 

Shell fragments; some sand grains 

Sand, dark gray; a few shell fragments 

Clay, blue; a little sand 

Sand, coarse, gray; some black grains 

Clay, light blue; a little sand 

Sand, coarse gray; some black grains 

Clay, blue; a little sand 

Sand, dark gray, calcareous; consolidated 

Sand, very dark gray fine grained; consolidated. . 

Sand, mixed light and dark gray 

Limestone, very sandy, gray 



Feet. 

15 

25 

60 

65 

77 

93 

103 

104 

119 

120 

170 

174 

201 

218 

265 



This well has a good flow of sulphur water, which rises to about 30 
feet above the surface. 



396 



GEOLOGY AKD GEOUND WATEKS OP FLORIDA. 



The first 93 feet is probably Pleistocene with possibly some Plio- 
cene. The remainder of the material is probably largely Miocene 
belonging to the Jacksonville formation. 

From an incomplete series of samples obtained in drilling a well at 
the Ponce de Leon Hotel at St. Augustine, Mr. Clapp compiled the 
following log : 

Record of well 1,400 feet deep at Ponce de Leon Hotel, drilled in 1886. 



Thickness. 



Depth. 



Sand with shell (surface water stops here). 
Clay, blue. 



Coquina. 

Sand 

Clay, iadvirated, and sand lumps. 
Clay, blue. 




Feet. 



Clay, black sand, and pieces of hard stone (50 gallons per muiute of sulphur water; 

water rises to +32 feet) 

Rock fsulphur water, 350 gallons per minute) 

Limesrone (1,800 gallons per minute; head +38 feet) 

Limestone (flow, 3,000,000 gallons per day) 

Limestone; rock 12 feet thick 

Limestone; dense light brown (sudden increase of water to 7,000,000 gallons per day; 

head + 42 feet; temperature, 79°) 

White chalk, green clay, and porous coral, dark in color 

(Sand pumping resumed at 557 feet, showing the limit of sulphur water is reached. 
Agam in coral full of fossils, early crinoid and pecten shells.) 

Limestone 

Seeps found here 

Hard drilling, probably chert 

Soft drilling again; sand pump brought up coral as before. 

still in water, below 

The rest of this record and samples were sent to World's Fair and never returned 



880 



170 
177 
350 
410 
495 

520 
557 



675 

685 



520 
,400 



The following log shows the nature of the material penetrated in 
drilliag a well 5 miles south of Hastings: 

Log of well 5 miles south of Hastings. 



Soil 

Sand, white 

Hardpan, black 

Quicksand 

Paint rock, yellow 

Quicksand 

Paint rock, red 

Clay, blue 

Flint 

Sand and shells. Drill dropped 3+ feet, water rising about to surface 



The following general log of materials penetrated at Hastings was 
supplied by Mr. I. C. Peck, a well driller: 

General log at Hastings. 

Feet. 

Sand 3 

Clay, red and yellow 6-15 

Sand, variable 5-20 

Clay, blue; extends to shell bed 20-30 

Shell bed, with first surface water; rock shell bed ^ to 8 feet 35-90 

Clay, blue, to rock; thickness variable. 

Rock, largely limestone with thin beds of chert. Source of water 

mostly limestone; in some wells white to grayish white 150 



Thickness. 


Depth. 


Feet. 


Feet. 


i 




6 


^ 


6 


12| 


18 


32J 


18 


50i 


20 


m 


20 


72i 


18 


90| 


n 


92 





















Depth 
to 

rock. 


Depth 
to prin- 
cipal 
supply. 


Quality of water. 


Yield 

per 

minute. 




Neare 
pos 

Anastas 


[ead 
Dove 
or 

3l0W 

rface.. 


Remarks. 


'^eet. 


Feet. 


Feet. 




Gallons. 




12 


145 


152 


Hard, sulxihur.. . 






Dinner : ^ 
Elkton.^ 2i 
Federal| 

Do>40 
Do.- 
Hasting[20 
Do.f26 
DO.-20 

DO.-24 
Hurds-.^ 6 

Do.- 




















250 


Sulphur 


500 
200 


Second supply at 200 feet. 


Hard, sulphur .... 


155 
150 
160 

140 



139 


155 


do 

do 


500 
600 


Second supply at 186 feet. 
Second supply at 183 feet. 






600 
Many. 

Many. 

Many. 

120 

Many. 


Near 

bottom. 

147 

180+ 

155 

130+ 


Sulphur 




do 




do 




Hard, sulphur, 

magnesia. 
do 




do 


Maximum head at 200 feet. 
















Brackish 


Many. 




Picolata 

St Anpi] 












1-2.00 




250+ 


Sulphur 






Do -23 






Corrodes metal. 


Do.-12± 
Do ^12± 




25O-500 
250-500 
1,350 

520 

520 
520 


Sulphur. 


1,400 
1,400 
5,500 


Strong flow about 500 feet. 
Do. 


. ...do 


Do.^ 
Do - 


Salt and sulphur.. 
do 


Minor supplies from about 
400 to 500 feet. Strong 
flow at 520 feet. 


Do!- 
Do - 


do 

do 






Do.- 

Do.- 
Do - 




do 


Many. 


Mouth of well a few feet 


15 ± 







*c 


above sea. Water, cor- 
rodes metai. 
Locality abandoned. 






Sulphur. . 




Do' 


175 





....,do 






Do - 






. . .do 




Do. 


Do r35 






do 


Many. 


Seven wells 


Do \- 










Do 1- 












Corrodes mr-tal. 


Do.- 
Do.. 

Switzerl- 
Do - 


33 








Many. 


Do. 








Do 


29 
30 




330 

280 


Soft, sulphur 

Soft. 


400 
400 











stimated. 



TypicaUoelh of St. John County. 




ST. JOHN COUNTY. 397 

The hard rock which caps the artesian bed is doubtless chert and 
the water-bearing rock is probably of Oligocene age. 

WATER SUPPLY. 

Source. — Good supplies of soft water are obtained from the Pleisto- 
cene sands which form the surficial deposits, but the supplies from 
the older geologic formations are much more extensively utilized. 
Both the Jacksonville formation and the Vicksburgian limestones 
yield artesian water. The Vicksburgian limestones afford more water 
than the younger rocks and they are usually regarded as the best 
source of supply. In the well at the Ponce de Leon Hotel the first 
flow is from the Jacksonville formation and the subsequent flows 
are from Vicksburgian limestones. 

Quality. — The Pleistocene sands furnish soft water. The Jackson- 
ville formation and the Vicksburgian limestones yield sulphur water, 
which becomes more highly mineralized with increasing depth. This 
fact is well shown by the log of the Ponce de Leon Hotel, where the 
deep suppHes are saline. 

Development. — In St. Augustine some old open wells walled 
with coquina are said to have been dug by the Spaniards. (See 
PL VI, B, p. 32.) At present the tendency is to sink deep wells, 
and these are more desirable than the shallow wells because they 
are not likely to be polluted by impure surface water. The supplies 
obtained from drilled wells are large enough to meet all demands and 
the head is sufficiently great to give good flows along the east coast 
and m the St. Johns River valley. On some of the high land which 
forms the divide between St. Johns River and the Atlantic flowing 
wells can not be obtained, but the water rises nearly to the surface 
and can be easily pumped. The supplies from all except the very 
deep wells are satisfactory for all purposes. 

There is a general lack of large springs in St. John County, though 
a large submarine spring is situated off St. Augustine. The water is 
said to emerge from an orifice about 65 feet in diameter and to rise 
with sufficient force to make the surface of the ocean immediately 
above the spring slightly convex. At the spring the sea is reported 
to be about 50 feet deep and the spring itself about 200 feet. 

The St. Augustine pubHc supply is obtained from flowing wells 
and is reported to be satisfactory. 



398 


GEOLOGY AND GROUND WATERS OF FLORIDA. 

General water resources of St. John County. 


r 




Topo- 
graphic 
loca- 
tion. 


Source of 
water. 


Surface 
formation. 


Shallow wells. 


Tovra. 


Depth. 


Supply. 


Quality 
of water. 


Principal 
water beds. 


Federal Point 


Plain. 

...do... 
...do... 


Wells and cis- 


Pleistoce n e 
sand. 
...do 


Feet. 
50± 

150-175 
10-15 


I 
L 


^mple. .. 




" Peninsular " 
limestone. 
Do. 
Do. 


Hastings 

St. Augustine.. 


terns. 
Drilled w 
PuhUc SI 
arte £ 
wells 
drilled 
driven 


ells... 


^aree 


Sulphur. 
Good.... 


ippiy 

ian 

and 

and 

wells. 


do 


Moderate . 




Deep wells. 


Aver- 

thick- 
ness of 
sand. 


Depth 
to water. 


Remarks. 


Town. 


Depth. 


Supply. 


Head 

above 

sea. 


Quality of 
water. 


Federal Point.. 


Feet. 
225-250 

200-f- 
200-1,400 


'Large'. 


Feet. 
30+ 

20± 
35-f- 


Sulphur 


Feet. 
50-f- 


Feet. 
4 

20 
Few. 


Supply constant. No 
sewerage system. 
Do. 


Hastings . . 


do 


St. Augustine.. 


Hard and sul- 
















phur. 











ST. LUCIE COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

St. Lucie County occupies a tract of land 15 to 30 miles wide, 
extending from the latitude of the northern end of Lake Okechobee 
northward to Brevard County. The coast is bordered by a long 
narrow bar, which is separated from the mainland by a shallow sound 
known as Indian River and is crossed by Indian River Inlet. This 
so-called river contains brackish water and has no perceptible current 
except that caused by winds and tides. On the mainland a short 
distance from the shore a ridge of nearly pure sand probably repre- 
sents a beach formed when the sea was farther upon the land than it 
is at the present time. Westward from this ridge the land is flat 
and low, rising in few places more than a few feet above sea level 
and nowhere reaching an altitude of 50 feet. The drainage of this 
lowland is very defective, the surface being covered with marshes, 
some of which are large. Locally shallow lakes are numerous, but 
most of them are small and unimportant. 

GEOLOGY. 

Gray sands of Pleistocene age cover the entire surface of St. Lucie 
County and in places are underlain by marls and coquina which also 
belong to the Pleistocene. At Fort Pierce the Vicksburgian lime- 
stones are buried beneath several hundred feet of younger beds, which 



ST. LUCIE COUNTY. 399 

doubtless include representatives of both the Miocene and Pliocene 
and the younger Oligocene forniations, but their discrimination niust 
await the collection of samples from drillings. 

At Ormond, in Volusia County, the Pleistocene sands and marls 
are at least 68 feet thick, and they are probably somewhat thicker 
in St. Lucie County. At Fort Pierce the Vicksburgian limestones 
were encountered at 670 feet. This leaves about 500 feet of strata 
of undetermined age. It is probably made up in descending order 
of Pleistocene, Pliocene, Miocene, and upper Oligocene formations. 

Log of well of St. Lucie Ice Co., Fort Pierce. 



Limestone, light bro-rni; with colorless quartz sand containing dark grains 

Quartz sand, colorless; containing dark grains 

Quartz sand, brown, ferruginous 

Quartz sand, colorless; shell and lime fragments 

Limestone, light gray, porous; shell fragments and sand 40 100 

Sand, calcareous 570 670 

Limestone, light gray; Vicksburgian fossils 142 812 



WATER SUPPLY. 

Source. — The water supplies of St. Lucie County are obtained 
from shallow wells in the Pleistocene sands and marls and rarely 
from the coquina and from deep wells in the Vicksburgian limestones. 
Water could doubtless be obtained in beds lying stratigraphically 
between the Pleistocene and Vicksburgian, but no effort has been 
made to develop these supplies. 

Quality. — The Pleistocene sands yield soft water. The water from 
the Vicksburgian limestone is free from danger of contamination 
but is highly mineralized and contains sulphur. At several horizons 
between the Pleistocene and the Vicksburgian limestones it should 
be possible to obtain water less highly mineralized. 

Development. — In St. Lucie County water is readily obtained at 
depths of less than 30 feet, but it is sometimes of doubtful sanitary 
quality. Flowing wells could probably be obtained in nearly all 
parts of the county, but the water is salt. However, artesian water 
is used at Fort Pierce and could doubtless be used elsewhere. 
76854°— wsp 319—13 26 




400 



GEOLOGY AND GROUND WATERS OF FLORIDA. 



! 




Typical well of Fort 

Pierce. 
Formerly740 feet, but 

continued to 812 

feet in 1904. 
Continued to 812 feet 

in 1904. 


S 


^ 1 3 1 




HI 1 1 


Depth 
to prin- 
cipal 
supply. 


1 


- : : 


Ill 


1? 1 . . 


Ele- 
va- 
tion 
above 
sea. 






0.9 


•g^oM : § 


■4i 




1 


1^ 00 00 00 


1 




iPfi 






do d 
1 • ■ 




c : fl : 
03 . : 03 . 

Hi II ; 


=0^ 


° d o d 

■g 73 TJ 'd 

MM 


II 




\i i 


1 


.as ^o : 
H pn M : 


^1 

II 


£ 

^ 


i i i 
1 



CO 





ill 


§ 


d o 


d d o 


o 1 




oqpQQQ 




iz; 




. >: 


4 






II 


i6 ■* ob<±> 




f^; 




1 


fio 






III 


3 ;;;;;; 

ft d d d d d d 


& 


CQ 


-o 'O T3 -o -rs -o 


ft 
































>. 


g 


; 












a 


S 


d d d c 


r 


d 




DQ 




'a'3T3t3'0'0 


t 


^.ji 


^(N 










§5 oc 












& 


^ 














i 














fe 


g 


■ 












































^ 


C 


• 












■— <T3 


bD ; 














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'3 


-s 


§ d d o o o o 
S -o Ti ts -^ T3 ro 




P^ 


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> 


•A*" M 












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-^ o o o o o o 1 






'OTf'O'C'O'a 1 




C^^ 


a 












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a 


W) o o o o o o 




1? 


'O'd'O'O'O'O 




w 








u- 


oooinoo 




5 


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iS 


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o 


« pf 


a 


















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CQ 




3 o o o o o o 






'C'OXJTJ'O'O 






















p: 












































































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■ s 










































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o 




. o 










^ 




"O 










eg 




: Q 












^ss^^A ! 






s 






a 












^ 


ilf 




; 


^S^d 


■^ 


d d d c 


c 


d 




^i^-^ 




-OTJ'O'ci'O'O 1 




^ 


: 














: 






; d 
































































o : fl 




g 




; 




13 ii-* 




^ 












F 
-S 
W 


h 


1— 


"3 
1 


1 


•■§ 



GEOLOGY AND GKOUND WATEKS OF FLORIDA. 401 

SANTA ROSA COUNTY. 
By G. C. Matson. 
GENERAL FEATURES. 

Santa Rosa County, near the western end of the State, comprises 
an area about 40 miles wide extending from the Gulf of Mexico north- 
ward to the boundary of the State, a distance of about 30 miles. In 
the northern part large areas are more than 200 feet in altitude, but 
near the coast the surface rises only a few feet above sea level. An 
extensive lowland terrace rising 20 to 30 feet above sea level stretches 
across the southern end of the county and along the principal streams ; 
it narrows gradually toward the north. Two other terraces, one 
40 to 60 feet and the other 70 to 100 feet in altitude, are extensively 
developed in southern Santa Rosa County and occupy narrow areas 
along the streams. In the southern part of the county, especially 
near YeUow River, extensive areas of swamp land lie only a few feet 
above sea level and after heavy rains are covered by a few inches to 
1 or 2 feet of water. The surface of the northern half of the county 
consists of rolling uplands crossed by the broad valleys of the prin- 
cipal streams and deeply dissected by the narrow channels of the 
minor streams. This upland evidently represents a former plain 
greatlj^ modified by erosion. 

GEOLOGY. 

The terraces of Santa Rosa County are composed of gray sand of 
Pleistocene age, which forms a continuous covering over all the low- 
land portion of the county. On the uplands gray residual sands are 
underlain by red, yeUow, and mottled sands and sandy clays belonging 
to the Lafayette ( ?) formation. This formation caps all the remnants 
of the upland plain and its eroded and redeposited materials are found 
in the valleys which cut that plain. The Choctawhatchee marl is be- 
lieved to reach the surface in the vicinity of MiQigan and to extend 
thence in a nearly continuous belt westward to the west boundary of 
the State. This formation is underlain by sands and marls belonging 
to the Alum Bluff formation and these in turn are probably underlain 
by the Chattahoochee formation. The Vicksburgian limestones un- 
derlie the entire county but are so deeply buried that it is impossible 
to obtain information concerning them. 

In the lowlands the aggregate thickness of the sands of Pleistocene 
age may be more than 50 feet. The average thickness of the Lafa- 
yette ( ?) formation is probably less than 30 feet, and its maximum is 
doubtless less than 50 feet. Practically no information could be ob- 
tained concerning the thickness of the Choctawhatchee marl and in- 



402 GEOLOGY AND GROUND WATERS OF FLORIDA. 

formation concerning the underlying formations is very meager. 
The marls and sands of the Alum Bluff formation doubtless attain a 
thickness of more than 50 feet and the Chattahoochee possibly of 
more than 100 feet. 

WATER SUPPLY. 

Source. — In the lowlands the gray sands furnish the greater portion 
of the supplies for the shallow wells, and throughout the upland por- 
tions of the county the Lafayette ( ?) formation is the principal source 
of supply for wells of moderate depth. Each of the older formations 
should contain an abundance of water, but as yet practically no relia- 
ble information is obtainable concerning their water-bearing capacity 
within the county. In other counties the Choctawhatchee marl and 
the marls and sands of the Alum BluflF formation are good water 
bearers, and satisfactory supplies may be expected from them in 
Santa Rosa. Both the Chattahoochee formation and the Vicksburg- 
ian limestones are known to be good water-bearing rocks and large 
supplies of water could doubtless be obtained from them in this county. 

Quality. — Soft water is obtained from the gray sand of Pleistocene 
age and generally from the shallow wells which penetrate the Lafa- 
yette ( V) formation. Moderately hard water may be expected from 
some of the deeper weUs in the sands and marls of the Choctawhatchee 
and Alum Bluff formations. All the water from the Chattahoochee 
formation and the Vicksburgian limestones would probably be hard 
and some of it might be saline. 

Development. — Most of the shallow weUs in Santa Rosa County go 
dov/n 15 to 35 feet, at which depth they procure large quantities of 
water suitable for both domestic and industrial uses. The water level 
is near the surface and the suppUes may be easily pumped. No deep 
weUs have been drilled, but several wells 75 to 100 feet deep have been 
sunk in the vicinity of Milton and Bagdad. All these wells obtain 
large quantities of excellent water, though some of it is reported to be 
moderately hard. There are three flowing wells in the swamps near 
Bagdad, but the yield is small and the head is sufficient to raise the 
water only a few feet above the surface. A similar flowing well with 
a very small yield has been drilled on the shore of Escambia Bay at 
Robinson Point. Doubtless other similar weUs might be obtained on 
very low ground either in swamps or along the coast. It is probable 
that deeper weUs on the lowland might obtain flows similar to those 
at Freeport, but as yet no wells have been drilled to sufiicient depth 
to test the matter. 



SANTA KOSA COUNTY. 
Typical wells of Santa Rosa County. 



403 



Nearest town 
or post office. 


Direc- 
tion and 
distance. 


Owner. 


Driller. 


Date 
sunk. 


Surface 
forma- 
tion. 


Geologic 
soxurce. 


Type of 
well. 


Use. 


Bagdad 

Do 


1 mUe 

west. 


W. Beard... 

J. C. Mac- 
Arthur. 

Stem-Culver 
Lamber Co. 

Chas. Sum- 
mers. 

W. J. WU- 
liams. 

Peter Toma- 
sello. 


MacArtl 
Owner. 


lur.. 




Pleisto- 
cene. 
...do 

...do 

...do 

...do 

...do 


Pleisto- 
cene. 
...do 

...do 

...do 

...do 

...do 


Driven. . 

Drilled.. 
...do 

Driven.. 

DriUed.. 
...do 


Domestic 




1905 
1908 


and stock. 
Do. 


Do 




Sampy 

Mac Arthur.. 


Boilers and 


Do 

Milton. 


1 mile 
west. 


domestic. 
D omestic 

and stock. 
Domestic. 






Sampy 


Turpentine 
still. 


Point. 






Nearest town 
or post office. 


1 


1 

ft 


1 
1 


•|i 


6 

1 


II 
It 


QuaUty 

of 
water. 


SI? 

as 

1 




Remarks. 


Bagdad 

Do 


Feet. 
75± 
30 

78 

74 
80 

112 


In. 

2 

11 


Feet, 
lb 
30 

78 

74 
80 


Feet. 
a 12 
a 10 

Few. 

a 12 
o20 

Few. 


Feet. 
+2 
-1-6 


Feet. 
75 
30 


Har 

Soft 
.d( 


d 


Feet. 


Gallons. 

1 

Few. 










Do 


■» 




10 wells. Water forms 


Do 


+6 
-5 


74 
75 

110 


Har 

Soft 

...d 


d 




10 
Few. 


some scale. 


MUton 

R obinson 


:>... 


35 


Typical weU at this local- 


Point. 

















General water resources of Santa Rosa County. 





Topo- 
graphic 
loca- 
tion. 










Surfa.ce forma- 
tion. 


Shallow wells. 


Town. 


Source of water. 


Depth. 


Water 
supply. 


Quality of 
water. 


Bagdad 

Chumuckla 


Plain.. 
...do... 
...do... 


Dug, driven, an 
Dug and drilled 
do 


ddriUed wells.... 
weUs 


Pleis 
d 


tocene 






Feet. 
15-75 
20-60 
30-55 


Large... 
Ample.. 
Good.... 




Milton 




d 


Hard. 




■ Deep wells. 


Average 
thickness 
of sand. 


Depth to 
water. 


Increase or 

decrease of 

supply. 


Sewerage 
system. 


Town. 


Depth. 


Water 
supply. 


Quality of 
water. 


Bagdad 


Feet. 
78 
80 
55-85 


Large 


Hard 


Feet. 


Feet. 
20 
18-30 
2.'i 


Slight 

None 

Slight 




Chumuckla 




40 


Do. 


Milton 


Large 


Hard 


Do. 

























404 GEOLOGY AKD GROUND WATERS OF FLORIDA. 

SUMTER COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Sumter County is in the central part of the peninsula on the western 
slope. A small area in the eastern part of the county rises more than 
100 feet above sea level and a large tract near the northwest corner 
has an altitude of less than 50 feet. 

A great deal of the county is very poorly drained and large shallow 
ponds are common. The southern and western boundaries are formed 
by Withlacoochee Kiver, near which the land is low and swampy. 
Lakes are common, the largest being Lake Panasoffkee, which drains 
to Withlacoochee River. 

GEOLOGY. 

Gray sands of Pleistocene age cover the entire surface of the 
lowlands and more or less effectually conceal the older formations. 
Beneath the gray sand is another sand of pale-yellow color which 
appears to be the result of weathering of the older geologic formations. 
This sand was doubtless derived from the upper Tertiary formations 
and owes its color to the presence of the hydrated iron oxide, which 
locally binds the material into a semi-indurated sandstone and 
renders much of it plastic. In many places a deposit of sandy 
kaolin underlies the hills, and similar materials are found in some 
of the depressions. 

The southeastern part of the county is underlain by the Apalachicola 
group, the rocks being referred to the Hawthorn formation, though 
they might with equal propriety be referred to the Alum Bluff or 
Tampa formation. The Hawthorn formation doubtless caps many 
of the higher hills, but its detailed distribution has not yet been deter- 
mined. A large portion of the county is underlain by limestones of 
Vicksburgian age. These limestones rise to the surface in the west- 
ern half of the county and dip gradually -to the south and east, 
where they pass beneath the Hawthorn formation. 

The Pleistocene gray sands are comparatively thin, in few places 
amounting to more than 10 to 20 feet and probably averaging less 
than 5 feet. Toward the southern end of the county they are 
believed to be thicker than farther north and they may be under- 
lain by sands and marls belonging to the Pliocene and Miocene. 
The yellow sands in few places attain a thickness greater than 10 to 20 
feet. The Hawthorn formation has been subjected to extensive 
erosion and hence varies greatly in thickness, in many localities 
comprising only a few feet of chert or clay resting on the Vicks- 
burgian limestones. Probably its maximum thickness is less than 
100 feet, though this is very uncertain, because the formation doubtless 
thickens toward the southeast corner of the county, where there are 



gUMTEH COUNTY. 405 

no well records. The Vicksburgian limestones are several hundred 
feet thick in Sumter County, but no reliable information is extant 
concerning the character of the older formations, because the base of 
the Vicksburg group does not appear to have been reached in the 
deepest wells. 

The most satisfactory well logs obtained in Sumter County are 
those constructed from samples collected while the wells were being 
drilled. Two of the logs are given below: 

Log of well of John E. Charles, at Oxford. 
[From samples of drillings in possession of the U. S. Geological Survey.] 



Thickness. 



Depth. 



No sample , 

Sand, coarse grained , yellow 

Sand, light yellow 

Clay, mottled green, sandy; with yellow streaks. 

Clay, green, sandy 

Clay, green and yellow 

Clay, green and yellow sand 

Sand, light gray to yellow 

Limestone, light gray, siiicified 

No samples 

Limestone, soft, white 

No samples 

Limestone, soft, light gray 



5. 


Feet. 


5 


5 


5 


10 


6 


16 


4 


20 


5 


25 


5 


30 


3 


33 


1 


34 


10 


45 


5 


50 


20 


70 


5 


75 


5 


80 



Water was obtained at 60 feet, but the principal supply was 
encountered at 80 feet. From 5 to 34 feet the material probably 
belongs to the Hawthorn formation and below 34 feet to the 
Vicksburg. 

Partial log of well of H. 0. Collier at Oxford. 

[From samples in possession of the U. S. Geological Survey.) 

Feet. 

Sand, light yellow 10-12 

Clay, green; with some sand 20-23 

Clay, dark yellow (weathered green clay) 24-25 

Clay, light yellow, sandy 28-29 

Sand, light yellow, with some clay 29-30 

Limestone, gray, weathered 35-36 

Limestone, soft, white 46-47 

Limestone, gray; shell fragments 65 

Limestone, soft, white 75 

Limestone, light gray to white; shell fragments 85 

Water was encountered at 56 feet, but the principal supply was 
obtained at 85 feet. The material represented between 10 and 30 
feet is thought to represent the Hawthorn formation. At 75 feet 
Vicksburg fossils were obtained and it is thought that the Vicksburgian 
limestones began at 35 feet. 



406 GEOLOGY AND GBOUND WATERS OF FLORIDA. 

WATER SUPPLY. 

Source. — Well records indicate that the Vicksburgian limestones 
are the principal source of water in Sumter County. Locally shallow 
wells may obtain water from the surficial sands or from the sandy 
beds in the Alum Bluff or Hawthorn formation. From conditions in 
the adjoining portions of Polk and Osceola counties, Pleistocene or 
late Tertiary beds may be important aquifers in the southeastern 
part of the county, but the possibility lacks confirmation because 
of the absence of wells in that region. 

Quality. — Some of the shallow wells in Sumter County obtain 
soft water from sand, but all the deeper ones get hard water, 
and even the shallow wells obtain hard water if they enter the 
Vicksburgian limestones. In general the Vicksburgian limestones 
furnish hard water and the younger formations soft water. At 
Sumterville a deep well found sulphur water at 1,400 feet, and all 
very deep wells will probably do the same. 

Development. — Driven or drilled wells 50 to 100 feet deep gen- 
erally obtain an abundant supply of hard water and some wells 
obtain good supplies at a depth of less than 50 feet. la a few 
localities soft water may be procured by wells 15 to 20 feet deep, 
but it is sometimes of doubtful sanitary quahty. 

The springs of Sumter County are not extensively utilized. Near 
Sumterville, water from Branch Mill Spring, owned by D. S. Belton, 
supplies power for a mill. The yield is reported to be 21,759 gallons 
per minute and the power is developed by constructing a dam across 
the stream. The water, which boils up, is hard, coming from the 
Ocala limestone. Its flow varies appreciably. 



Nearest town or 
post office. 



Center Hill. 

Do 

Do 

Do 

Do 

Coleman... 
Oxford 

Do 

Do 

Do 

Do 

Do 

Do 

Do 

Do 

Do.... 



Do 

Sumterville . 
Do 



Webster. 
Do.. 
Do.. 
Do.. 
Do.. 
Do.- 



;pth 
Dirto 
dck. 



2^ mi^- 
2 mil^- 
Near 4- 

■:::il 

h mile- 



20 



i mile- 
Near, 
. . . .dr 
....d(- 
l mil€ 
1 mile- 
Near .- 

dr 

dr 



70 



imil^- 
Near|- 
21 mi- 



Near 
^ 

Near 
I mil 
d 



70S54°-— WSP 



Depth 

to 
prin- 
cipal 

supply. 



Feet. 
32 



55 



225 
110 

86 
76 
92 
86 
81 
92 



130 



68 



Protec- 
tive 
clays. 



Yes. 
Yes. 



Yes. 
Yes. 
Yes. 
Yes. 
Yes. 
Yes. 
Yes. 
Yes. 
Yes. 
Yes. 

Yes. 
Yes. 



Yes. 
Yes. 
Yes. 
Yes. 



Quality of 
water. 



Hard 

Iron 

Hard 

do 

Slightly hard. 

Hard 

do 

do 

do 

do 

do 

do 

do 

do 

do 

do 



do.. 

do.. 

Sulphur. 



Hard 

do 

do 

do 

do 

do 



Remarks. 



Water incrusts boilers; yield, 
50 gallons per minute. 



Starts ia Pleistocene; draws 
from Vicksburgian lime- 
stones. 



Typical wells of Sumter County. 





Direction and 
distance. 


owner. 


Driller. 


Date 
simk. 


"S.°' 


Use. 


Depth. 


Diam- 


Casing, 


Eleva- 
tion 
above 


Heads- 




X 

Aft. 


Protec- 
clays. 


Quality or 
water. 


" - 


post office. 


Above 


Below 
surlace. 




Remarks. 




2.1 miles iiorlh 

jmiio'wesV.::::::: 


R n Bona 


1). S. Spratling 

J. ir. Eobbms 

F.D.Smith 

.1. U. Robbms 

w.i':iia"miii;on:;:::;; 

K. l,.Frcverraenl.h.... 

iiarl^^&miver;;;;;;: 

,j,^.^do..._._. 


1905 

IS 

1900 
1907 

1907 

SS 
1905 

1893 

1907 

1905 


Driven.... 

:;;::doV.V-' 
'i)riiie°i:::: 
Dfined:;:; 

....do 

:::;:do::::: 

DiS-.-;;; 

Drilled.... 
do 




'"fi 

h 

225 

92 

81 
92 

72 

86 
2,002 

72 

42 
50 


2 


F<H. 
4.5 
22.5 

03 


.„,. 


Fed. 


Feci. 

62 
50 

60 


Fret. 
' 20 


Ffd. 

110 
70 

92 


Yes::: 
ves::: 

"?ef::: 

Yes... 

Yes::: 
Yes::: 
^^es::: 

Yes... 

?S::: 




no'.,:; : ; ■; 
o"fo"d.";.;:; :: ; : 

Do 

Do 


I'M). Smith 

J. W.Smith 

VenaiiloiHarkness... 
Coleman CjTro.ss Co... 

Sl:!i.Sir;::;:::::: 
.^:!;i^^"^;:;;;;;;; 

do 


.-..,do 

irrigatim,' .";:::::::::: ■ 

--'™d".:;::::;:::::;.: 
:::::dll:::::::::::::::: 
.'"^i°"::::::::::::: 


J|'- 

"100 
°>.79 

!Iioo 


50 
= 45} 


"on'!::::::-:: 

Hard 

siightrviiaRi:: 

--."'.do:::::: 

:::::do::::::: 

:::::;lo:::::: 

:::.::IC::::::- 

:::::t::::::: 

do 

suiphurV.::::: 

Hard 

do 

::::::lo:::::::: 
t 








B.L. Freyerment'h 

do 


Irrigation 




Do:;:::::::;::; 


iT'sSr 




Do . 


do 

|^,niienort.west... 






74 






Sunset Lumber & 
uf^%'^r.o., 


W.F. Hamilton 


General mill purposes . 


10" 

2^ 
11 


74 


Water incrusts boilers; vtoUl, 
50 gallons per mimite; 


sumtoVuio:::::;: 








Do 


21 miles south 

Near 


Pearson Oil & Gas Co. 
J. W. Fussell 

do 










Starts in PloisUicene; draws 
Irom Vicksburglan lime- 






do 




General 

Irrigation 

Household 

do 


130 


89 




s? 




130 


Yes... 
Yes... 

?S::: 


Do . 








Nea?;omhea,t:;" 
J mile west 


j:yT.RobbinsV.v.:::: 


1906 
1907 


do 

do 

::.'.":do::::: 


30" 


i 




'"■■■s?- :::;::: 




Do 






























' 









(To faco pfige40f».) 



SUMTER COUNTY. 
General water resources of Sumter County. 



407 





Topographic 
location. 


Source 

of 
water. 


Shallow wells. 


Town. 


Surface formation. 


Depth. 


Supply. 


Quality of 

water. 


Principal 
water bed. 


Center Hill 


RolUng 

do 

do 

Level 

Roiling . 


Wells . 
...do... 
...do... 
...do... 
.do... 


Some clays. . 


Feet. 


Fair... 
...do... 
...do... 
...do... 
.do... 


Soft 


Limestone 


Coleman 

Oxford 


do 

do 

do 

.do.. .. 


'"15^20' 


'soft 


Do. 
Do 


Panasoffkee 

Sumterville 


do 


Do. 
Do 


Webster 

Wildwood 


Level 

do 


...do... 
...do... 


do 

do... 


" "20^36" 


...do... 
.do.. 




Do. 
Do 













Deep wells. 


Depth to 
rock. 


Depth to 
water. 




Town. 


Depth. 


Supply. 


Head 

above 

sea. 


Quality 
of water. 


Remarks. 


Center Hill . 


Feet. 
55 

225 
110 


Abundant . 

...do 

...do 


Feet. 
70-75 


Hard.... 


Feet. 


Feet. 
14 

6-10 

50-60 

50 


No sewerage sys- 
tem. 
Do. 
Do. 
No sewerage sys- 
tem; typhoid not 
prevalent. 
No sewerage sys- 
tem. 
Do. 


Coleman. 

Oxford 


...do..... 

...do 

...do 


0-50 
20-75 


Sumterville 




■ 

.do 




.do 


0-50 


Webster . 




.do 


75-80 


do 




Wildwood 




...do 


...do 






Do. 



















408 GEOLOGY AND GROUND WATERS OF FLORIDA. 

SUWANNEE COUNTY. 
By G. C. Matson. 
GENERAL FEATURES. 

Suwannee County is at the northern end of the peninsula near the 
Georgia line. Its surface is generally roUing and weU drained, though 
in some parts sink holes, small lakes, and ponds are common. The 
areas bordering Suwannee and Santa Fe rivers and their principal 
tributaries are less than 50 feet above sea level, but the upland 
has an elevation of over 100 feet and a large tract in the northeastern 
part of the coimty of over 150 feet. 

GEOLOGY. 

Below the 100-foot contour the surface of Suwannee County is cov- 
ered by gray sand belonging to the Pleistocene. The uplands are 
covered by a thin mantle of residual sand, underlain by red, yellow, 
and mottled sands and sandy clays of the Lafayette (?) formation, 
resting on light-colored sands and clays belonging to the Alum 
Bluff formation. These deposits overlie limestones belonging to the 
Hawthorn formation. Near LuravUle and in the southeast corner 
of the county the Vicksburgian limestones appear at the surface, 
but elsewhere they are for the most part buried beneath the younger 
formations. 

Little is known concerning the thickness of the geologic forma- 
tions in Suwannee County. The thickness of the Pleistocene sand 
ranges from a few to about 20 feet, averaging probably not more 
than 15 feet. The Lafayette (?) formation has a thickness amount- 
ing to 30 feet or less and the Alum Bluff formation is somewhat 
thicker. The thickness of the Hawthorn formation varies greatly, 
the maximum being not far from 100 feet. The Vicksburgian lime- 
stones are doubtless several hundred feet thick, but owing to the 
absence of good well logs it is impossible to obtain local information 
concerning them. 

WATER SUPPLY. 

Source. — ^The sands of the Lafayette ( V) and Alum Bluff formations 
will furnish abundant water for shallow wells; and it is probably 
these sands that are penetrated by many driven wells. The lime- 
stone of the Hawthorn formation is also a good water-bearing bed, 
but the best source of underground water in Suwannee County is the 
Vicksburgian limestones. 

Quality, — Some of the water from the Lafayette (?) and Alum 
Bluff formations is soft, but a part of it is hard, as is the water from 
all the older formations. In addition, much of the water from the 



SUWANNEE COUNTY. 409 

older rocks is sulphureted, a condition especially true of that from 
the Vicksburgian linaes tones. 

Development. — For dornestic and farm uses shallow wells obtain 
ample supplies of water at depths of 10 to 30 feet. Driven wells 
50 to 100 feet deep yield larger supplies, but their water is usually 
hard and some of it contains sulphur. At Lake City a well sunk to 
a depth of 1,080 feet yields highly mineralized water, which, how- 
ever, is reported satisfactory for use as a city supply. 

Springs are numerous in Suwannee County, especially along the 
rivers which border the county. The one best known is the Suwannee 
Sulphur Springs, a mile northeast of Suwannee. This spring emerges 
from Oligocene limestone and discharges hard sulphur water at a 
rate estimated at 52,000 gallons per minute. There is a hotel near 
the spring and the locality is used as a pleasure resort. The Newland 
Spring near Falmouth emerges from Oligocene limestone and has a 
flow of hard water estimated at 100,000 gallons per minute; no use 
is made of this spring. 

Flowing wells can not be obtained in Suwannee County, but the 
supply of water available for wells which enter the Vicksburgian 
limestones is practically unUmited. These limestones should be 
reached by wells varying from a few feet at Luraville to over 200 
feet deep in the central and northern parts of the county. 



410 



GEOLOGY AKD GROUND WATERS OF FLORIDA. 



o o o o 



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coi> t^ o 



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SUWANNEE COUNTY. 



411 



W)3 >. 









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412 



GEOLOGY AND GROUND WATEES OF FLORIDA. 





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Luraville.. 
O'Brien.... 
Pinemount. 
Suwannee.. 

Welborn... 



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GEOLOGY AND GKOUND WATERS OF FLORIDA. 413 

TAYLOR COUNTY. 
By G. C. Matson. 
GENERAL FEATURES. 

Taylor County borders the Gulf at the northern end of the penin- 
sula of Florida. A broad terrace 20 to 25 feet above sea level extends 
back several miles from the coast, another rises to a height of 40 to 
60 feet, and a third has an altitude of 70 to 100 feet; each occupies 
a large area in the southern portion of the county. The eastern 
boundary is formed by Steinhatchee River and the western boundary 
by Aucilla River. In addition to these streams, the county is crossed 
by FenhoUoway and Econfina rivers. Though the streams are 
sufficiently numerous to insure good drainage, there are large areas 
of swamp land near the coast and near the northern boundary of the 
county. South of Perry there are many lakes of moderate size. 

GEOLOGY. 

Gray Pleistocene sand forms the surface over much of the county, 
and, though thin, it is so uniformly distributed as to obscure the 
underlying beds. The Alum Bluff and Hawthorn formations are 
believed to underlie a large portion of the county, though definite 
information could be obtained at a few localities only. The Vicks- 
burgian limestones are exposed in the phosphate pits at FenhoUo- 
way, where they are covered by a few feet of limestones belonging 
to the Hawthorn formation. 

Little is definitely known concerning the thickness of the several 
geologic formations in Taylor County. The average thickness of 
the surficial sands is probably several feet, and the sands may be 
underlain by several feet of older sands and marls. The Hawthorn 
formation is believed to be comparatively thin, and the Vicksburgian 
limestones doubtless are several hundred feet thick. 

WATER SUPPLY. 

Source. — ^The surficial sands are an important source of water 
supply, though the underlying sands and limestones also yield 
abundantly. In many wells it is difficult to determine just what 
formations supply the water, though probably most wells depend on 
the limestones of the Hawthorn formation. The Vicksburgian lime- 
stones are doubtless the best water-bearing beds of Taylor County, 
and they should be more extensively utihzed. 

Quality. — ^The surficial sands supply an abundance of soft water. 
The limestones of the Hawthorn formation and the sands of the 
Alum Bluff formation supply hard water, some of which may contain 
sulphur. The Vicksburgian limestones supply hard sulphur water, 



414 



GEOLOGY AND GKOUND WATERS OE FLORIDA. 



which may locally contain some salt, especially where the wells 
are deep. 

Development. — The shallow wells of Taylor County range in depth 
from about 15 to 30 feet, and the water level is near enough to the 
surface to permit easy pumping. Most of the wells are less than 100 
feet deep, though at Perry two wells exceed 200 feet. These deeper 
wells are regarded as the most satisfactory, because when properly 
cased they are not likely to become polluted. Flowing wells may 
possibly be obtained on low ground near the coast, but as yet no 
attempt has been made to drill any such. The beds which supply the 
strong flows in Franklin County probably underlie Taylor County 
at a depth of less than 500 feet, and if flows are procured the water 
beds should be encountered between 300 and 500 feet. The town 
of Perry has a public supply obtained from a drilled well. The 
quantity is ample to meet all the needs of the town, and the water, 
though hard, is satisfactory. 

Taylor County has a number of small springs which are being 
utilized for bathing and drinking, the most important being at 
Perry, Fenholloway, and Hampton Springs. 



I 



Typical wells of Taylor County. 



Nearest, town or 
post otfice. 



Direction and 
distance. 



Owner. 



Driller. 



Date 
sunk. 



Type of 
well. 



Fenholloway 

Hampton Springs. 

Do 

Lake Bird 



i mile west 

I mile northwest., 

do 

Near 



Do. 
Luther. 



....do 

1§ miles northwest . 



Perry.., 
Do. 



I mile northwest . 



Do. 
Do. 



Tedder Lumber Co.. 
Powell & McLean Co . 

do 

Dowling Naval 

Stores Co. 
Lake Bird Lbr. Co. . . 
Powell & McLean Co. 



Maloy Bros 

Perry Ice & Power 
Co. 

..-.do 

....do 



Owners 

G. P. Payne. 
do 



1906 
1906 
1906 



Owners 

McMuUen & Faulk- 
ner. 
H. J. McMullen.... 
John Cole 



1907 
1904 



Owners . . . 
John Cole . 



1905 



1905 
1906 



Driven. 
Drilled. 

Do. 

Do. 

Driven. 
Drilled. 

Driven. 
Do. 

Do. 
Do. 



Nearest town or 
post office. 



Fenholloway. 



Hampton Springs. 

Do 

Lake Bird 

Do 

Luther 

Perry 



Do. 
Do. 



Use. 



Sawmill 



General 

do 

Turpentine still 

Sawmill 

Turpentine still 

Livery stable 

City supply; ice man- 
ufacturing. 
Not in use 



Domestic and stock. . . 






22 



Pro- 
tecting 

clays 
present. 



Yes. 



Some 
Yes.. 



Some 
No!!-' 



Quality 

of 
water. 



Hard; 
some 
sulphur 

Medium 

Hard... 

...do.... 



Soft 

Hard.... 
Hard.... 
...do 



...do 

Sulphur. 



Remarks. 



Tncrusts boil- 
ers. 



Do. 

Incrusts boil- 
ers badly. 

Starts in Pleis- 
tocene. 



TAYLOK COUNTY. 



415 



I 



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76854°— wsp 319—13- 



-27 



416 GEOLOGY AND GROUND WATERS OF FLORIDA. 

VOLUSIA COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Volusia County comprises a large area between St. Johns Riv( 
and the east coast. Near the coast the surface rises only a few fee] 
above sea level, but farther west a sand ridge extends from Osteen 
to the northern boundary of the county between Lake George and 
Dunns Lake. The islands and bars of the coast are covered by dune 
sands, but they have a smooth, hard beach, which is unexcelled for 
carriages and automobiles. The mainland is bordered by an ancient 
beach ridge, which rises about 25 feet above sea level and extends for 
several miles parallel to the coast. Back of this ridge is a broad tract 
of low land, which is partly covered by water during wet seasons and 
contains many extensive areas of swampy land. Along St. Johns River 
is a low terrace which corresponds to the ridge bordering the east 
coast. Both ridge and terrace were formed during the late Pleisto- 
cene, when some of the present land was beneath the sea. 

GEOLOGY. 

The surficial formation of Volusia County consists of gray Pleisto- 
cene sand, which is locally underlain by coquina and shell marl of 
Pleistocene age. Beneath the Pleistocene sands and coquina are 
sands and shell marls of Pliocene age (Nashua marl), and these are 
in turn underlain by marls and perhaps by limestones of Miocene age 
(Choctawhatchee marl). Both the Miocene and Pliocene are exposed 
in the St. Johns Valley and both are known from well samples at 
De Land. From a shell marl at Daytona and in well samples from 
Ormond Vaughan identified fossils which he believed to be Pliocene. 
The upper Oligocene formations may be represented in Volusia 
County, but they have not been detected in any of the well samples, 
and it appears probable that locally the Miocene (Choctawhatchee 
marl) rests directly on the Vicksburgian limestones. This would mean 
that the upper Oligocene rocks had been removed by erosion before 
the deposition of the Choctawhatchee marl. 

In Volusia County the thickness of the younger formations is diffi- 
cult to determine, because th^ey can not be readily discriminated. 
The Pleistocene sands are at least 68 feet thick at Ormond, but they 
pass downward into shell marl which can not be easily distinguished 
from the underlying Pliocene, and the Pliocene marls are so much like 
those of the Miocene that they can not be differentiated in well logs. 
The thickness of the entire series of beds from the top of the Pleisto- 
cene to the base of the Miocene is apparently less than 150 feet. 



VOLUSIA COUNTY. 



417 



Beneath the Miocene the Vicksburgian limestones are doubtless 
several hundred feet thick. 

A general log of materials penetrated at Daytona is given below. 
This information is of exceptional value because it was furnished 
by Bellew and Milton, who have drilled many wells at that locality. 

General well log at Daytona. 

Feet. 

Sand, or sand and sliells 35-56 

Clay, very light blue ; no sand 14-30 

Sand and shells 5-18 

Limestones, soft; with layers of hard chert 1^ to 2 feet thick indefinitely 
below. 

The first three members of this log probably include the Pleisto- 
cene, Pliocene, and Miocene. The limestone is believed to belong to 
the Vicksburg group. 

Log of well of Florida East Coast Hotel Co., at Ormond. 
[Prepared from well samples.] 



Thickness. Depth, 



Shell sand 

Marl, gray; Cardium shells 

Bits of large shells 

Wood fragments in sand 

Limestone, gray, shelly; shells of Nassa. 
Limestone, she'll rock, shells of Natica. . . 

Limestone, soft, shelly 

Limestone, Avhite, rotten, marly 

Limestone, light buff, rotten 




Feet. 
'56 



92 
106 
110 
150 
200 
275 



Vaughan identified shells from 56 to 66 feet that indicate that the 
material to a depth of 66 feet is Pleistocene. From 66 to 90 feet the 
material may be either Pleistocene or Pliocene. From 90 to 150 feet 
the material is of uncertain age. Below 150 feet the limestones are 
probably of Vicksburg age. 

Log of the city well at De Land. 
[Prepared from well samples.] 



Thickness. 


Depth. 


Feet. 


Feet. 


12 


12 


10 


22 


14 


36 


18 


54 


36 


90 


20 


110 


60 


170 


39 


209 


21 


230 


20 


250 


14 


264 



Sand, white 

Clay, yellow, sandy 

Shell marl 

Shell marl and sand 

Limestone, soft, cream-colored; with shell fragments 

Limestone, gray 

Limestone, hard, gray and cream-colored 

Limestone, hard, light brown 

Limestone, hard, white to brown 

Limestone, hard, white to brown, porous 

Limestone, soft, white, fossiliferous 



418 GEOLOGY AKD GBOUND WATEBS OF FLOEIDA. 

Water was encountered between 80 and 135 feet and at 160 feet. 
It rose to within 29 feet of the surface. Another supply at 207 feet 
rose to within 27 feet of the surface. 

From the samples obtained between 22 and 54 feet Vaughan 
identified Pliocene fossils. In the sample obtained between 54 and 
70 feet he identified Miocene shells. This indicates that both the 
Nashua and Choctawhatchee marls are present at De Land and gives 
some idea of their minimum thickness at that locality. 

WATER SUPPLY. 

Source. — Many shallow wells in Volusia County obtain water from 
the gray sands of Pleistocene age. Deeper wells reach supplies in 
the Nashua and Choctawhatchee marls. The deep wells penetrate 
limestones which are in part of Vicksburgian age, though some of 
them doubtless obtain water from younger rocks. Unfortunately, in 
many wells it is impossible to determine the exact age of some of the 
limestones. 

Quality. — The water from the Pleistocene sand is soft, but that 
from the Nashua and Choctawhatchee marls is hard and locally con- 
tains sulphur. The limestone waters are hard, and in most localities 
they contain sulphur. Salt is common in some of the deep waters 
that penetrate the Vicksburgian limestones, and it occurs sporadically 
in the water from other formations. 

Development. — ^Volusia County contains a large number of deep 
wells, many of which yield excellent flows. The depth of the flowing 
wells varies greatly, being as low as 20 to 45 feet in localities like 
Enterprise and Ponce Park. On the east coast good flows are usually 
obtained at 80 to 150 feet, though larger yields are procured with 
increasing depth, and some wells are several hundred feet deep. 

The head of the flowing wells varies from place to place. At Day- 
tona it was formerly about 17 feet above the sea, but it has gradually 
declined until at the present time it is rarely more than 14 J feet. The 
loss of head appears to be due to the withdrawal of large quantities 
of water. There are said to be about 1,000 wells in and near the 
town, and there must be at least several hundred, most of which are 
allowed to flow uninterruptedly, wasting a large quantity of water. 

At HoUyhill, just north of Daytona, and at Ormond and Port 
Orange the conditions are very similar to those in Daytona. At 
New Smyrna the conditions are like those at Daytona, except that the 
head is probably slightly greater and there is no marked evidence of 
decline. (See PL XVI, B, p. 230.) At Seabreeze, on the island 
opposite Daytona, the head of the water is lower and the flows are 
smaller than at Daytona. 

At Oak Hill the artesian wells are about 130 feet in depth and the 
head is sufficient to give good flows. The water is said to contain 












— 





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VOLUSIA COUNTY. 419 

some salt. The locality is apparently near the northern border of the 
area of saline water. (See p. 226.) At Coronado some good flows are 
obtained at about 100 feet. The depth required to give good flows 
at Ponce Park ranges from 45 to over 100 feet, and at Enterprise the 
range is still greater. The shallow wells at Enterprise and Enter- 
prise Junction probably obtain their supplies from the Pleistocene 
sands or from the Pliocene and Miocene sands and marls. 

In the vicinity of De Land wells do not yield flows except near the 
river. The water level in the deep wells is usually several feet below 
the surface at De Land, Stetson, Lake Helen, and Orange City, this 
being due to the fact that these towns are situated upon high ground. 

The present development is sufficient to indicate the possibilities 
of obtaining good supplies of water. There is little incentive to deep 
drilling, because the deeper waters are highly mineralized and are 
locally saline. The best opportunity for improvement is to prevent 
excessive waste of water, and this could be done by closing wells 
when they are not in use. Many owners hesitate to check the flow 
of water because they fear that the wells will become clogged, though 
there is little or no danger of this if the wells are properly cased. 

Volusia County contains some good springs and some deep wells 
which supply mineral water. De Leon Springs, a mile northwest of 
the town of the same name, supplies sulphur water, which is exten- 
sively used. A bathhouse and a swiniming pool have been con- 
structed at the spring, and the water, having a uniform temperature 
of 76°, is very satisfactory for bathing. A 100-foot well near De Land 
Junction, known as Deerfoot Spring, yields water highly charged 
with sulphur and believed to have medicinal properties. The well 
is located in the woods a mile south of Beresford and is not used. 

Near Enterprise a flowing well 20 feet in depth, supplying excellent 
salt-sulphur water, is known as the Benson salt spring. 

The Orange City Mineral Spring water is obtained from a well 117 
feet deep. The quantity is large enough to supply the town, but the 
water level is about 20 feet below the surface and hence it is necessary 
to use a pump. 

A public supply at De Land is obtained from deep wells. The 
water is pumped to a standpipe and is distributed by gravity. The 
suppHes at both Orange City and De Land are satisfactory. Seville 
formerly had a pubUc supply, but it has been abandoned on account 
of decrease in population. 



420 



GEOLOGY AKD GKOUND WATEBS OF PLOEIDA. 



Springs of Volusia County. 



Name. 



Owner. 



Nearest 

town or 

post office. 



Direction 

and 
distance. 



Discharge 

per 
minute. 



Topographic 
surround- 



Use. 



Deerfoot Spring 
D e L e n 
Springs. 

Benson Salt 
Springs. 

Orange City 
Mineral 
Spring. 



J. B. Taylor... 
Volusia 

County 

Bank. 
Emma Tack- 

er and A. 

M. Stead. 
Orange City 

M in e r al 

Springs Co. 



Beresford . . . 

D e L e n 

Springs. 

Enterprise.. 
Orange City. 



1 mile south.. 
1 mile north- 
west. 

\ mile west. . . 
i mile south.. 



Gallons. 
Small. 



20 



In valley 

D e pression 
in side of 
valley. 
Slight de- 
pression. 

Gently un- 
dulating. 



Not used. 
Drinking. 

Intend to 
ship. 

Drink ing, 
public sup- 
pis'-, and 
irrigation. 



Name. 



Deerfoot 
Spring. 

D e L e o n 

Springs. 

Benson Salt 
Springs. 

Orange City 
Mineral 
Spring. 



Emergence. 



Flowing well. . 

Boils up from 
22-foot hole. 

Flowing well. . 

Pumped 



Varia- 
tion. 



Seasonal 



Some. 



Improvement. 



None. 



Bathhouse 
and swim- 
ming pool. 

None 



Quality of 
water. 



Sulphur. 
do... 



Sulphur and 
salt. 



Tempera- 
ture. 



76 



Remarks. 



Not muddy after 
rain. No con- 
tamination near. 
Do. 



Do. 
Do. 



WAKULLA COUNTY. 

By G. C. Matson. 



GENERAL FEATURES. 

Wakulla County, on the Gulf coasts extends from Ochlockonee 
River eastward to beyond St. Marks River. Its coastal portion com- 
prises broad swamps rising only a few feet above sea level. Inward 
the surface remains flat for many miles and then gradually becomes 
more diversified with roUing sand ridges and hiUs. The broad flat 
which borders the coast is a terrace formed during Pleistocene times 
when the land was submerged. Toward the northern corner of the 
county the land rises to over 50 feet above sea level, and another 
broad terrace represents a stUl more extensive submergence of the 
land. 

GEOLOGY. 

Gray Pleistocene sand covers the surface of Wakulla County. 
Toward the northern end the gray sand is underlain by yeUow and 
red sands and sandy clays which rest upon limestones. The ''Sop- 
choppy limestone '^ is extensively developed along the river of the 
same name. The Chattahoochee formation is weU exposed along the 
railroad south of Tallahassee and probably underlies at no great 
depth the entire surface of the county. The Vicksburgian limestones 



WAKULLA COUNTY. 



421 



also underlie Wakulla County, but they are not known to reach the 
surface. 

The average thickness of the Pleistocene sands is less than 5 or 6 
feet, but locally the thickness attained naay exceed 40 to 50 feet. 
The red and yellow sands which underlie the sands of Pleistocene 
age near the northern end of the county do not attain any great 
thickness. The combined thickness of the ''Sopchoppy limestone '^ 
and the Chattahoochee forniation is probably more than 200 feet and 
may amount to over 300 feet. Beneath these limestones are the 
Vicksburgian limestones with a thickness which has not been deter- 
mined, but which probably amounts to several hundred feet. 

WATER SUPPLY. 

Source. — The surficial sands are the source of an abundant supply 
of water in aU parts of Wakulla County, and the '^Sopchoppy lime- 
stone" and Chattahoochee formation are also good water-bearing 
formations. The Vicksburgian limestones will furnish more water 
than any of the other formations, and the supplies should be satis- 
factory unless obtaiaed at too great depths. 

Quality. — ^The surficial sands supply soft water. The deeper sup- 
plies obtained in Wakulla County will undoubtedly be hard and 
many of them will contain hydrogen sulphide. 

Development. — Nearly aU the weUs in Wakulla County are shallow. 
This is largely due to the fact that an abundance of water may be 
obtained within a few feet of the surface, and hence it is not con- 
sidered necessary to drill deep wells. The only deep well reported 
from the county, that of the Coast Cypress & Railroad Co.,^ has 
a diameter of 6 inches and a depth of more than 252 feet (to rock) and 
contains water that is said to be both salt and sulphur. Its curb is 
4 feet above sea level and its head is 5 feet below the curb. Flowing 
wells can probably be obtained on low ground near the coast. The 
exact depth necessary to obtain flows is somewhat uncertain, though 
judging from the conditions in Franklin County it should be possible 
to procure flows at 325 to 400 feet. On the high ground flows could 
not be obtained, but the same supplies which are obtained from 
flowing wells should rise near enough to the surface to permit them 
to be pumped without great expense. 

General water resources of Wakulla County. 





Topo- 
graphic 
location. 


Source of water. 


Surface 
formation. 


Water 

beds 

in shallow 

wells. 


Deep wells. 


Sewerage 
system. 


Town. 


Supply. 


Quality 
of water. 


St. Marks.. 


Flat 


Cisterns and springs. . . . 


Limestone 


Limestone 


Abvmdant. 


Hard.... 


None. 



1 Water-Supply Paper U. S. Geol. Survey No. 102, p. 254. 



422 GEOLOGY AND GKOUND WATEKS OF FLORIDA. 

Springs of Wakulla County. 



Name. 



Owner. 



Nearest town 
or post office. 



Discharge 
per minute. 



Topographic 

svirround- 

iBgs. 



Use. 



Emergence. 



Wakulla. 



Brewer Sul- 
phur. 
Do 



Mrs.C.A.Slos- 

son. 
Nathanie 1 

Brewer. 
do 



Crawf ordj 

ville. 
Newport... 



Gallons. 
Very large... 

Small 



.do. 



T. H. Hall. 



Very large. 



Swampy 

do 

Pine woods. 



None 

Domestic. 

Not used. 
Medicinal 



Boiling. 



Do. 



Name. 



Wakulla. 



Brewer Sul- 
phur. 
Do 



Geologic source. 



Probably Chatta- 
hoochee forma- 
tion. 



Chattahoochee 
formation. 



Improvements. 



None. 



Private bath- 
house. 
None 



Hotels, resort, 
etc. 



Quality of 
water. 



Lime. 



Sulphur, iron 

Slight sul- 
phur. 
Soft.variable 



Tem- 
pera- 
atiu-e. 



70 



Stream. 



Large.., 

Small... 
...do..... 



Remarks. 



Remote from con- 
tamination. 



Do. 



WALTON COUNTY. 

By G. C. Matson. 
GENEEAL FEATURES. 

Walton County extends from the Gulf of Mexico to the northern 
boundary of the State and is bordered on the east by Holmes and 
Washington counties and on the west by Santa Kosa County. Its 
surface ranges in altitude from about sea level near the coast to nearly 
300 feet above the sea near the northern boundary. The southern 
portion of the county consists of broad flat terraces formed when the 
sea stood farther inland than at present. There are three of these 
terraces, having altitudes of 20 to 25 feet, 40 to 60 feet, and 70 to 100 
feet. Terraces also occur along the large streams of the county, 
merging with those just mentioned. A ridge of high land extends 
from near Deerland eastward beyond De Funiak Springs. Other level 
tracts are numerous, especially in the northern part of the county, 
where they form more or less extensive table-lands, rising in places 
from 200 to over 250 feet above sea level. Near the coast the land is 
low and swampy and contains a few shallow lakes. There are also a 
few small lakes in the northern part of the county, and swamps are 
not uncommon along the larger streams. At Natural Bridge a small 
stream flows through a channel in the limestone. In the southern 
part of the county a large arm of the sea is known as Choctawhatchee 
Bay. 



WALTON COUNTY. 423 

GEOLOGY. 

The terraces in Walton County are mantled gray sand of Pleistocene 
age. On the uplands residual sand is underlain by red, yellow, and 
gray sands and sandy clays referred to the Lafayette ( ?) formation, 
which is extensively developed north and for several miles south of 
the Louisville & Nashville Railroad. In the southern haK of the 
county a broad belt is underlain by the Choctawhatchee marl, which 
doubtless dips southward beneath the younger formations but which 
is seldom recognized, because it is deeply buried and it is not easily 
identifiable in well drillings. The Choctawhatchee marl is underlain 
by marls, sands, and clays belonging to the Alum Bluff formation, and 
these materials outcrop at intervals north of the exposures of the 
Choctawhatchee marl. The Chattahoochee formation underlies the 
surficial formations in the northern part of the county and dips south- 
ward beneath the Alum Bluff formation. At Natural Bridge the 
Vicksburgian limestones are exposed. These rocks underlie the 
Chattahoochee formation throughout the county. 

The average thickness of the Pleistocene gray sand is probably 
about 25 feet on the upland and it thickens abruptly toward the south. 
Near the southern margin of the county there is no information con- 
cerning the exact thickness, and it is thought it may locally extend 
to a depth of over 50 feet. The Lafayette ( ?) formation is well devel- 
oped; it probably attains a maximum thickness exceeding 50 feet and 
it averages at least 30 feet. The thickness of the Choctawhatchee 
marl is probably more than 50 feet and the marls of the Alum Bluff 
formation may attain a thickness of over 100 feet, though they seldom 
exceed 50 feet. Data are lacking to determine the thickness of the 
Chattahoochee formation and the Vicksburgian limestones, but it 
should amount to several hundred feet. 

Log of the well at the De Funiak Springs waterworks. 



Depth. 



Sand, surface 

Clay, reddish, sandy 

Sands, white and yellow 

Marl, blue, containing thin layers of fossil shells 

Sand.s, white, containing some layers of yellow clay 

Shale, indurated, yellowish, sandy, at 408 feet , 

Sands, containing fossils ana yielding considerable water , 

Sandrock, light colored , 

Shale, blue, containing water 

Sandrock, light gray, containing the principal water supply 

The water in this well rises to within about 150 feet of the surface 
and is very soft. The well will yield over 110 gallons per minute. 




424 GEOLOGY AND GKOUNB WATERS OF FLORIDA. 

WATER SUPPLY. 

Source, — The Pleistocene gray sands are comparatively unimpor- 
tant on the uplands, but on the lowlands they yield abundant water 
within a few feet of the surface. The sands and sandy clays of the 
Lafayette ( ?) formation are usually water bearing and yield excellent 
supplies. The Choctawhatchee marl is probably a good aquifer, but 
the number of wells drawing from it is small. The marls and sands 
of the Alum Bluff formation yield good supplies, which are utilized 
for farm and domestic purposes. Both the Chattahoochee formation 
and the Vicksburgian limestones are excellent sources of water, though 
in Walton County only a few wells have been drilled into these rocks. 

Quality. — Both the Pleistocene and the Lafayette (?) formation 
supply soft water. The water from the Choctawhatchee marl and the 
marls and sands of the Alum Bluff formation is probably soft, though 
locally moderately hard water might be encountered in these forma- 
tions. Both the Chattahoochee formation and the Vicksburgian 
limestones should yield moderately hard water; but apparently the 
limestones are partly replaced by sands and sandstones, and the water 
from these is reported to be soft. 

Development, — Throughout the lowland portion of Walton County 
shallow wells obtain abundant supplies of water within a few feet of 
the surface, but on some portions of the upland such wells may need 
to be sunk to a depth of over 60 feet. In general, however, good sup- 
plies can be obtained at moderate depths and the presence of more or 
less clay above the water beds, especially in the upland portions of 
the county, protects the water from contamination by impure surface 
drainage. 

Very few deep wells have been drilled in Walton County, except in 
the vicinity of Freeport, where some good flowing wells range in 
depth from 180 to 188 feet. The well of A. F. Murray at De Funiak 
Springs is 210 feet deep, but the water supply used is obtained within 
60 feet of the surface. The total depth of the well at the city water- 
works in De Funiak Springs is 610 feet. Reference to the log previ- 
ously given wiQ show that several water beds were encountered and 
that the best one is near the bottom of the well. At Lakewood, near 
the northern end of the county, the Britton Lumber Co. has a well 
604 feet in depth. This is the only deep well reported in that portion 
of the county, but the yield is sufficiently large to indicate that good 
supplies may be obtained by drilling such wells. The exact aquifers 
penetrated by the flowing wells at ^Freeport and Whitfield could not 
be determined ; the wells yield moderately hard sulphur water suitable 
for all purposes. 

The city supply at De Funiak Springs was established after the close 
of the field work for this report, and accurate information concerning 



WALTON COUNTY. 



425 



it is wanting. At Freeport a large number of houses are supplied 
with water from flowing wells, which have a maximum head of about 20 
to 22 feet, sufficient to carry the supply through the mains to near-by 
dwellings. Similar flowing wells could probably be obtained along 
the entire southern border of the county. 

The large spring at De Funiak Springs is really a small lake. The 
water is remarkably free from inorganic materials and the quantity is 
very large. Fluctuations in the level of this lake are governed by the 
relative amounts of evaporation and rainfall and the surface of the 
ground water in that vicinity doubtless changes in sympathy with the 
level of the lake. Water from a smaller spring, located near the 
western edge of the town and owned by the Beach-Rogers Lumber Co., 
is used at the sawmill and in the principal hotels of the town. The 
spring discharges more than 2 gallons a minute of moderately hard 
water, boiling up from sand. It is improved by a pumping plant and 
spring house. The water is not muddy after rain. No source of 
pollution is near. 

Typical wells of Walton County. 



Nearest town 
or post office. 



Direction 

and 
distance. 



Owner. 



Driller. 



Date 
sunk. 



Surface 
formation. 



Type of 
well. 



Use. 



DeFuniak 
Springs. 



A. F. Murray. 
do 



Owner. 
do. 



1907 



Freeport.... 

Do 

Do 

Do 

Lake wood. . 
Laurel Hill. 
Whitfield... 



3 miles south 



4 miles east 
of south. 



Blackman & 

McLean. 
Graves & 

Tatum. 
J.J.McCaskle, 



F. J. White 

&Co. 
....do 



Pleistocene. 
....do..... 

....do 

....do 



.do. 



Town. 



Near. 



Britton Lum- 
ber Co. 
Hart 



1905 



Jemigan Lum- 
ber Co. 



.do., 
-do., 
.do., 
.do. 
.do.. 



Drilled.. 
Dug 

Drilled.. 
...do.... 
...do.... 
...do.... 
...do.... 

Dug 

Drilled. . 



Not used. 

Domestic 
and stock. 

Public sup- 
ply. 

Boilers and 
domestic. 

Boilers. 

Public sup- 
ply- 
Boilers and 

drinking. 
Hotel and 

stock. 
Drinking. 



Nearest town 
or post office. 



De Funiak 
Springs. 

Do 

Freeport 

Do 

Do 

Do 

Lakewood... 
Laurel Hill.. 

Whitfield.... 



Depth. 



Feet. 
210 



60 



188 
188 



180 
604 
57 

180 



Di- 
ame- 
ter. 



Inches. 
3 



8 
10,6 



Casing. 



Feet. 



183 



180 
188 



-180 
604? 



180 



Ele- 
va- 
tion 
above 

sea. 



Feet. 



a 10 



a 10 
ad 



a 10 

b290 

235 

as 



Head 
above 

or 
below 
sur- 
face. 



Feet. 



48 



+ 28 
+ 18 



- 15 
■160 
■ 45 



Depth 
to prin- 
cipal 
supply 



Feet. 



183 



180 
180 



160 
604 



180 



Mineral 

character 

of 

water. 



Hard. 



...do.... 
Sulphur. 



..do.... 



Sulphur. 



Soft 

Sulphur. 



Yield 

per 

minute. 



Gallons. 



180 



200 
175 



125 
250 



Remarks. 



Drilled in bottom of 
next well. 

Second supply at 80 

feet. 
Forms scale. 
Small flow at 150; no 

scale noted in 

boilers. 



Forms soft scale. 
Typical well of this 

locality. 
Forms scale. 



o Estimated. 



b By barometer. 



426 GEOLOGY AND GKOUND WATERS OF FLORIDA. 

General water resources of Walton County. 





Topographic 
location. 


Source of water. 


Surface 
formation. 


Shallow wells. 


Town. 


Depth. 


Supply. 


Qual- 
ity of 
water. 


Principal 
water 
beds. 


Lakeview . . 
Laurel Hill. 


Rolling 

Gently roll- 
ing. 


Dug wells and one 
drilled well. 

Dug and bored wells. 


Pleistocene.. 
do 


Feet. 
14-24 

20-60 


Ample . . 
...do.... 


Soft... 
...do.. 


Marianna 
1 im 6- 
stone. 
Do. 





Deep wells. 


Average 
thick- 
ness 
sand. 


Depth to 
water. 




Town. 


Depth. 


Supply. 


Head 

above 

sea. 


Quality of 
water. 


Remarks. 


Lakeview.. 
Laurel Hill. 


Feet. 
608 


Large... 


Feet. 
160 


Hard 


Feet. 
15± 


Feet. 
15 ± 
10 


No sewerage system. 
Do. 

















WASHINGTON COUNTY. 

By G. C. Matson. 
GENERAL FEATURES. 

Washington County occupies a large area bordering on the Gulf 
coast in west Florida. Its topography is greatly diversified, ranging 
from low, flat lands near the coast to high, rolling uplands farther north- 
ward. The southern part of the county consists of a broad, nearly level 
terrace rising 20 to 30 feet above sea level. North of this terrace 
there is a second terrace at an altitude of 40 to 60 feet, and still farther 
inland a third terrace rises 70 to 100 feet above sea level. Along 
the principal streams broad flats correspond in a general way with 
the terraces near the coast. At Caryville a terrace along Choctaw- 
hatchee Kiver is 72 feet in altitude, and at Vernon a terrace on 
Holmes Creek rises to about 50 feet. Similar though less extensive 
terraces exist along the smaller streams of the county. The uplands 
represent the edge of an extensive plain which extends northward 
into Alabama, and which near its southern edge has been eroded 
into rounded hills separated by deep valleys. 

GEOLOGY. 

The terraces of Washington County are composed of gray sand of 
Pleistocene age. This sand covers all the older geologic formations 
except on the uplands, where there is a thin mantle of residual sand, 
underlain by red and yellow sands, sandy clays, and sandstones 



WASHINGTOISr COUNTY. 



427 



referred to the Lafayette ( ?) formation. The Choctawhatchee marl 
is the surface form.atioii in a belt several miles wide, extending nearly 
east and west across the central portion of the county. Marls, sands, 
and clays belonging to the Alum Bluff formation underlie the Choc- 
tawhatchee marl. North of the area of Choctawhatchee marl a large 
part of the county is underlain by the Chattahoochee formation, 
though in the vicinity of Duncan, Wausau, and Chipley this formation 
has been removed, exposing the Vicksburgian limestones, which 
underlie the other formations throughout the county but are not 
known to be exposed except at the localities mentioned. 

On the uplands the surficial sands are comparatively thin, but 
toward the southern end of the county the sands of Pleistocene age 
may reach a maximum of several feet. The average thickness of the 
red and yellow sands and sandy clays of the Lafayette ( ?) formation 
is probably more than 30 feet and the maximum is believed to exceed 
50 feet. Some uncertainty exists about the thickness of the Choctaw- 
hatchee marl, but, including the marl which may belong to the Alum 
Bluff formation, it probably exceeds 50 feet. The thickness of the 
Chattahoochee formation is variable, the average probably being less 
than 100 feet and the maximum over 200 feet. The Vicksburgian 
limestones doubtless have a maximum thickness of several hundred 
feet. 

Log of the well of the Wood Lumber Co. at Caryville. 



Thickness. 



Depth. 



Sandrock, yellowish 

Rock, pinkish, flinty 

Limestone 

Sand, fine, white 

Limestone, becoming rotten at bottom 

Clay, brownish 

Sandstone, gray 

Limestone and marl , 

Sand, water rose to a point 10 feet below the surface 

Marl 

Sand, greenish 

Marl and clay 

Limestone and marl 

Sand, gray; present water supply 

Sandstone 

Clay and marl 

Sandstone • 

Clay 

Limestone 

Marl and clay ■- 

Sand 

Sandrock 



Feet. 





Feet. 


25 


25 


8 


33 


18 


51 


18 


69 


89 


108 


-30 


138 


4 


142 


80 


222 


10 


232 


60 


292 


20 


312 


140 


452 


80 


532 


23 


655 


7 


562 


no 


672 


8 


680 


17 


697 


18 


715 


32 


747 


17 


764 


32 


796 



In this well the Pleistocene sand appears to have a thickness of 25 
feet and to be underlain by 26 feet of limestone belonging to the 
Chattahoochee formation. Beneath this last are the rocks of Vicks- 
burg age, and it is thought that the well may pass through these into 
older geologic formations. 



428 ' GEOLOGY AND GROUND WATERS OF FLORIDA. 

WATER SUPPLY. 

Source. — The gray sands are not important aquifers on the uplands, 
but on the lowlands they contain abundant supplies within a few feet 
of the surface. The sands of the Lafayette ( ?) formation are a very 
important source throughout the upland portion of the county. The 
Choctawhatchee marl furnishes an abundance of water, which, how- 
ever, is little utilized. Large quantities of hard water may be 
obtained from the Chattahoochee formation, but deep wells are 
usually sunk to the Vicksburgian limestones and these rocks are 
regarded as the best water-bearing beds of the county. 

Quality. — The sands of the Pleistocene and Lafayette (?) forma- 
tion supply soft water. Little is known concerning the quality of the 
water from the Choctawhatchee marl and the Alum Bluff formation, 
but it is probably moderately hard. Both the Chattahoochee forma- 
tion and the Vicksburgian limestones furnish hard water. Near the 
southern end of the county deep wells may encounter salt water, but 
in general the supplies contain only a moderate quantity of mineral 
matter and are satisfactory. 

Development. — In Washington County most shallow wells obtain 
abundance of water within 30 feet of the surface. Many of the wells 
do not exceed 10 feet, but in a few places it is necessary to sink 
moderately deep wells and probably the maximum depth of the 
shallow weUs is not far from 50 feet. A few deep wells have been 
drilled in Washington County and they have been uniformly success- 
ful. They range in depth from 160 to 757 feet, but good supplies 
may usually be obtained at less than 300 feet. The only flowing 
well reported is at MillviUe; it is 206 feet deep and its head is said to 
be 10 feet above the surface. It is probable that flowing weUs could 
be obtained on the low ground near the coast and that the water would 
usually be satisfactory. 



WASHIKGTOISr COUNTY. 



429 





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430 



GEOLOGY AND GEOUND WATEBS OF FLORIDA. 





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; Supply varies with 

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INDEX. 



A. Page. 

Abes Spring, section at 130 

Acknowledgments to those aiding 17-20 

Adams Spring. 415 

Agassiz, A., cited 177-178, 179, 180, 185 

Agassiz, L., cited 180, 185, 188 

Alachua, rock at 74 

wells at, data on 266 

record of 264 

Alachua clay, character of 66, 69, 141-142 

distribution of .' 143-144 

fossils of 142 

soil from 39, 40 

stratigraphie position of 142 

structure of 143 

water in 245, 252 

See also particular counties. 

Alachua County, description of 263 

geology of 263-265 

public water supply in 254 

sinks in 263 

view of 26 

springs in 266, 267 

water supply of 265-267 

wells in, data on 254, 266 

records of 264 

Alachua sink, description of 27 

location of 263 

Alafla River, rocks on 146 

Albion, wells at and near 355, 356 

Allay, E. C, cited 207 

Allen, J. H., cited 102 

Alliance, wells at 32^330 

Alluvial deposits, distribution and character 

of 159 

Altamont Springs, spring at 378 

Altha, wells at.... 279 

Altitudes, distribution of 21-23, 45, 54-55, 61 

Alton, wells near 337 

Altoona, wells at 343 

Alum Bluff, rocks at and near 108, 132 

section at and near 109-110 

Alum Bluff formation, character of 67, 

69,109-111,246,250 

deposition of ■ ? 203 

distribution of 111-117 

fossils in Ill 

members of 108 

description of 117-121 

stratigraphie position of 108-109 

structure in Ill 

water in 246, 248, 250-251 

See also particular counties. 

Aluminous clay, correlation of 127, 129, 131 

Alva, well at 348 

Anastasia Island, coquina on 192 

coquina on, views of 80, 148 

wells near 396 

76854°— wsp 319—13 28 



Page. 

Anthony, wells at and near 367, 368 

Antioch, well at 322 

Apalachicola, depression near 213 

public water supply at 254 

wells at 305-308 

record of . .*. 306 

water in, head of 237 

Apalachicola group, deposition of 202-203 

formations of 66^67, 69-70, 246 

description of 87-121, 202, 246 

nomenclature of 85-87 

springs from 229 

water in 246,248-250 

See also particular counties. 

Apalachicola River, rocks at and near 108, 132 

sections at and near 19-110 

Apopka, springs near 378 

wells at 378-379 

Arcadia, public water supply at 254 

rocks near 134, 138 

wells at and near 294-296 

record of 389 

Arcadia marl, correlation of 69, 134 

Archer, rocks near 91 

wells at 266 

Area of southern Florida 42 

Argyle, section near 121 

wells at 326-327 

Armstrong, well near 396 

Amo, wells at 266 

Arredonda, wells at 266 

Artesia, wells at 276 

Artesian water, areas of, distribution of 236- 

237,259 

conditions for 234-235 

figure showing 234 

fallacies concerning 241-242 

head of, changes iu 237-241 

changes in, figure showing 240 

controlling factors in 234r-235 

height of, in Florida 236-237 

relation of, to depth of well 241-242 

See also Flowing wells. 

Aspalaga Landing, rocks at and near 99 

sections at and near 98-99 

Astor, well at and near 342,343 

Astor Park, well at and near 342 

Aubumdale, wells at 390 

Aucilla, wells near 333 

Avoca, well at 315 

Avon Park, wells at 296 

Aycock, public water supply at 254 

well at 328 

B. 

Bagdad, wells at and near 402-403 

Babia Honda, nature of 62 

rocks on 188 

431 



432 



INDEX. 



Bailey, J. W., cited 75,102 

Baker County, description of 267 

geology of 267-268 

water supply of 268-269 

Baldwin, wells at and near 299, 300, 301 

Ballast Point, rocks at 105 

Banyan, wells at 276 

Bars, occurrence and character of 37 

Bartow, public water supply at 254, 390 

rocks near 74,388 

wells at and near 390 

Bass, rocks at 92 

wells at • 287 

Bayard, wells at 300,301 

Bay City, wells near 318 

Bay Port, springs near. .- 317,319 

Beach deposits, character of 160 

view of 62 

Bed rock. See Rock. 

Belleair, public water supply at 254, 323 

well near 322 

Belleview, wells at and near 367, 368 

Benson Salt Springs, occurrence and character 

of 420 

I, well at 418-420 

T, Dr., cited 256 

Bibliography of region 17-19 

Big Blue Spring, occurrence and character of. 334 
Big Cypress Swamp, location and extent of. . . 58 

Big Pine Key, location and character of 61 

rocks near 182, 188 

springs on 371 

wells on 170,372 

water of, assays of 260 

Biscayne Bay, pineland near 52,53 

rocks near 51 

springs near 256 

Black Creek, rocks on 126 

section on 126-127 

Blackwelder, E., cited 183 

Blair, wells near 271 

Blountstown, wells at 279 

Blue Spring, occurrence and character of 356 

Bluffsprings, wells at.. 304 

Boardman, wells at 368 

Bone Valley, wells at 390 

Bone Valley gravel, character of. 66, 69, 145-146, 206 

deposition of 206 

distribution of 146 

fossils of 146 

nomenclature of 144-145 

stratigraphic position of 145 

structure of 146 

water in 245,253 

Bonifay, wells at 326,329-330 

Bored wells, use of 231-232 

Bostwick, wells at 392,394 

Boulware Spring, occurrence and character of. 267 

Bowling Green, wells near 294r-296, 390 

Boyd, wells at 415 

Bradentown, public water supply at 254, 364 

soils near 40 

wells at and near 364 

water of, head of 237 

Bradford County, description of 269 

geology of 269,270 

public water supply in 254 



Page. 

Bradford County, springs of 270,272 

water supply of 270-272 

Branford, wells at and near 410, 412 

Brevard County, description of 273 

geology of 273, 275 

springs of 276 

water supply of .• 275-277 

wells in, records of 274, 275 

Brewer Sulphur Spring 422 

Bridges, natural, occurrence and character of. 28-29 

Bristol, wells at 358 

Bronson, spring near 355,356 

Brooksville, rocks near 316-317 

wells near 318-319 

Brown, wells at 287 

Brownville, well at 294 

Bryceville, wells at 375 

Buckingham, wells near 348 

Buck Key, rocks on 195 

well on 172-173,348 

record of 172 

water of, assay of 260 

Buena Vista, wells at 293 

Bulow, well at 418 

Bumside, well at, record of 299 

C. 

Calhoun County, description of 277-278 

geology of Ill, 278 

water supply of 278-279 

Callahan, public water supply at 254-374 

wells at 374-376 

Caloosahatchie marl, character of 66, 69, 135 

distribution of 136-138 

fossils of 135 

nomenclature of 134 

stratigraphic position of 134^135 

structure of 135-136 

water in 245 

Caloosahatchie River, rocks on 136, 175 

sand dunes near 48-49 

sections on 136,137 

Calvary, wells at 368 

Campbell, wells at and near 380 

Campbellton, wells at 329-330 

Canaveral Lighthouse, wells at 276 

well at, record of 274 

Cantonment, rocks near 130 

well near, record of 303 

Cape Canaveral, coast at 36,39 

See also Canaveral Lighthouse. 

Capes, formation and character of 38-39 

Cape Sable, ridges at 49 

wells at and near 371 

water in, assay of 260 

Cape St. George, formation of 39 

Cape San Bias, formation of 38-39 

Captiva, well near 348 

Carrabelle, wells at and near 305-308 

wells at and near, record of 305 

water in, head of 237 

Carraway, wells at 394 

CarrsMill, geology near Ill 

Carters Mill, wells at 389,390 

Caryville, rocks near 101 

well at 429-430 

record of 427 



INDEX. 



433 



Page. 

Cassidy Spring, location of 334 

Cattle ranges, location of 50 

Caverns, occun'ence and character of 26 

Caximbas Pass, sand dunes near 48 

Cedar Key, spring near 356 

wells at and near 354-356 

Center Hill, wells at and near 406, 407 

Century, wells at 304 

Cerithium rock, correlation of 70, 102, 103 

Chaires, well at 352,353 

Channels, underground, occurrence and char- 
acter of 26, 229 

Charlotte Harbor, rocks near 137 

wells near 294, 295 

Chassahowitzka Springs, occurrence and 

character of 281,282 

Chattahoochee, wells at and near 310-312 

Chattahoochee formation, character of. 70, 94-95, 246 

correlation of 86, 87 

disposition of 203 

distribution of 96-101 

fossils of 95-96 

nomenclature of 93 

stratigraphic position of 93-94 

structure of 96 

view of 94 

water in 246,248,249 

See also particular counties. 

Chattahoochee Landing, rock at 93 

section of 96-97 

Chemical deposits, occurrence and character 

of 161-162 

Cherry Lake Spring, description of . . .'. 361 

Chimney rock, occurrence and character of. . . 78 

China, oolite from 183 

Chipley, public water supply at 254 

rocks near 427 

section near 150 

wells at 429, 430 

Chipola group or stage, correlation of 69, 86 

Chipola marl member, distribution and 

character of 108, 117-119 

fossils in 118 

Chipola River, rocks on 101, 118, 130-131 

natural bridge on 28-29, 74 

sections on 119, 130, 131 

Choctawhatchee marl, character of. . 69, 127-129, 246 

distribution of. 66, 130-133 

fossils of 12^130 

stratigraphic position of 127-128 

structure of 130 

water in 246, 251-252 

See also particular counties. 

Choctawhatchee River, rocks on 101 

Chumuckla, wells at 403 

Citra, wells at 368 

Citrus County, description of 280 

geology of 280 

springs of 281, 282 

water supply of 281-282 

Clapp, F. G., cited 84 

work of 18, 19 

Clark, wells at 266 

Clarksville, section near 132 

wells at 279 



Page. 

Clay, distribution and character of 156 

soil from, distribution and character of . . 41 

water-bearing quality of 242-243 

Clay County, description of 283 

geology of 283-284 

public water supply in 254 

springs of 284-285 

water supply of 284-285 

Clayland, wells near 410 

Clearwater, public v/ater supply at 254, 323 

rocks near 107 

section near 107 

well at 322, 324 

Clyatt, wells at 266 

Coast, artesian head on 236-237 

features of 35-42, 44, 63 

topogi-aphy of 35, 44, 62-63 

wells on 167-175 

See also Coastal swamps. 

Coastal Plain, nature of 21 

Coastal swamps, distribution and character of. 58-59 

Cocoa, wells at 276, 277 

Cocoanut Grove, springs at 289 

rocks at 178 

wells near 292 

Coleman, wells at and near 406, 407 

Columbia, weUs at 288 

Columbia County, description of 286 

geology of 286-287 

public water supply in 254, 287 

springs of 287 

water supply of 287-288 

Concord, wells at 311-312 

Conrad, T. A., cited 71, 180, 184 

Continental border, submerged, occurrence 

and character of 35-36 

Cdquina, deposition of 216 

distribution and character of 155-156, 

157, 174, 175, 192-193 

marl from 40 

views of 80, 148, 154 

Coral reefs, occurrence and character of 35, 

42, 197-198 

view of 62 

Coronado, weUs at 418, 419 

Cortez, well at 364 

Courtenay, wells at 276, 277 

Cottondale, rocks near 328 

wells at and near 329-330 

CrawfordsviUe, spring at 422 

Crescent City, public water supply at 254, 393 

weUs at 392-394 

Crestview, geology near 129 

Croom, rock near 79 

wells near 31&-319 

Crowders Crossing, deposits at 120 

Crystal River, springs near 29, 281, 282 

wells near 281, 282 

Culture, development of 43 

Currents, ocean, work of 38-39, 6-3-64, 216 

Cypress, wells at 329-330 

Cypress swamps, occurrence and character of. 58 

D. 

Dade City, wells near 386-387 

Dade County, description of 288 

geology of 

springs in 



434 



ii!n>Ex. 



Page. 

Dade County, water supply of 289-293 

wells in 289-293 

flows from 258, 292 

records of 289-291 

water of, assays of 260 

Dall, W. H., fossils determined by 97, 151 

on Apalaehicola group 86-87, 

90-92,96-97, 102-103, 105, 108-110 

on geologic history 203, 209, 212-213 

on Miocene series 125, 127, 128, 130-133 

on Pliocene series 134-138, 140-144 

on Quaternary rocks . . 151, 156, 160, 189, 190, 198 

on structure 164-165 

on Vicksburg group 71, 72, 74, 76, 80-82 

work of 17 

Dan,W.H., and Stanley-Brown, J., cited 112-113, 129 

Dams, eflect of, on head 241 

Dana, J. D., cited 186 

Dania, geology near 178, 183, 195 

wells at and near 179, 290, 293 

record of 290 

Darlings Slide, section at 131 

Darton, N. H., cited 168 

Data, source of 17 

Day, wells near 337 

Daytona, rocks at 416 

submarine spring near 236 

wells at and near 418 

record of 417 

water in, head of 2S6, 239, 418 

Daytona Beach, wells at and near 418 

Deerfoot Spring, description of 419, 420 

De Funiak Springs, public water supply at . 254, 425 

rock near 121 

section near 149 

spring at 425 

weUsat 424-425 

record of 423 

De Land, public water supply at 254, 419 

rocks near 133, 138, 416, 418 

wells at and near 418-420 

record of 417 

De Land Junction, wells near 418, 419 

De Leon Springs, rock near 88, 91 

rock near, view of 140 

section near 140 

spring near 419, 420 

Delesse, A., on ground water 221 

Delray , rocks near 177, 180, 192, 195 

wells at and near 167, 174, 384-385 

record of 384 

De Soto County, description of 294 

geology of. 294-295 

public water supply in 254 

water supply of 295-296 

Development, cultural, progress of 43 

Devils Mill Hopper, location of 263 

rock at 90 

Diatomaceous earth, occurrence of 159 

Dinner Island, wellnear 396 

Double Sink, well near 355 

Dowling Park, wells at and near 410, 412 

Drainage, description of 23-25, 43, 54-55 

Drainage, undergrotmd, description of 25-29, 52 

Drew, G. A., cited 161, 162, 200-201 

Drilled wells, use of 232-233 



Driven wells, use of 232 

Dug wells, use of 231 

D uncan, rocks near 78, 427 

Dunedin, wells at and near 322, 324 

Dvmes. See Sand dimes. 

Dunnellon, public water supply at 254, 367 

wells at and near 367, 368 

Dutton, wells at 266 

Duval County, description of 296-297 

geology of 297-299 

public water supplies in 254, 300 

springs of 300 

water supply of 299-301 

wells in, records of 298, 299 

E. 

Eagle Lake, wells at 390 

Early Bird, wells at 368 

East Eau Gallie, well at 276 

East Mayport, wells at 300 

Eau Gallie, rocks near 153, 273 

wells at 276, 277 

records of 274, 275 

water of, head of 236, 275 

Ecphora beds, correlation of 69, 127 

Eden, wells at and near 400 

Edgar, wells at 392, 393 

Ehren, wells near 386-387 

Eldred, wells at 399 

Eldridge, G. H., cited 27, 155, 171 

work of 17 

Eleanor, wells at 326-327 

Elevations, distribution of 21-23, 45, 54-55, 61 

Ellabee, wells near 271 

EUaville, rocks near 359 

springs near 360 

wells at 360-361 

Ellenton, rocks near 108, 116, 362 

sections near 116, 117 

soU near 41 

wells near 364 

Elzey, wells at and near 355, 356 

Emerson, wells at and near 410 

Enterprise, salt water at 227 

wells near 418, 419, 420 

Enterprise Jimction, well at 418 

Eolian deposits, occurrence and character of. 160-161 

Erosion, features of 30, 51-52 

Escambia County, description of 301-302 

geology of 77, 302-303 

public water supplies in 254 

soils of 40-41 

water supply of 304 

wells in, records of 303 

Espiritu Santo Spring 323, 324 

Estero, wells at and near 348 

wells at and near, record of 346 

Estiffanulga, wells at 358 

Etna, wells near 281 

Eureka, wells at 368 

Eustis, diatomaceous earth near 159 

wells at 342,343 

records of 339-340 

Everglade, geology at 174, 190 

well at, record of 346 

Everglades, bedrock in 51, 55-57 

character and extent of 53-54, 159 

drainage of 41, 54-55, 255 



INDEX. 



435 



Page. 

Everglades, elevation of 54, 255 

explorations In 43 

origin of 57-58, 216 

section near, figure showing 58 

soils of 41 

water of 255 

Everglades limestone, correlation of 68 

Evinston, wells at 266 

F. 

Falmouth, spring near 409 

wells at and near 410,412 

Federal Point, wells at and near 396, 398 

Felicia, wells near 281 

FenhoUoway, springs at 414, 415 

wells near 414 

Femandina, public water supply at 254,374 

wells at 374, 376 

record of 374 

Fertilizers, use of 41, 42 

Fivay, wells near 386-387 

Flamingo, wells at 371 

Flatlands, distribution and character of 50 

Fiorahome, wells at. 392,394 

Floral Blufi, wells near 300 

Floral City, wells near 281,282 

Florida, cooperation of 18 

Florida, central and northern, geography of. . 21-42 

geology of 65-211, 212-214, 216-218 

Florida, southern, geography of 42-64 

geology of 167-212,214-218 

waters of 255-262 

Florida reef, description of 61, 182 

geology of 187-188, 197-198 

growth of 185 

wells on 371 

Floridian group, correlation of 69, 134 

Flowing wells, effect of pumping on 239 

occurrence of 233 

See also Artesian water. 

Foerste, A. F., cited 74 

Ford Spring 267 

Fort De Soto, well at, record of 321 

Fort George, wells at 300 

Foit Lauderdale, dunes near 48 

rock near 57, 177, 178-179, 180 

submarine springs near 289 

wells at and near, data on 178, 179, 293 

records of 289,290 

Fort McCoy, wells at 368 

Fort Meade, wells at 296, 390 

Fort Myers, rocks near 51 

section at 348 

wells at and near 345,348 

records of 349 

water in, assays of 260 

head of 237, 345, 348 

quality of 260, 348, 349 

Fort Ogden, wells at and near 294-296 ■ 

Fort Pierce, rocks at 398-399 

well at 399-400 

record of 399 

Fort Reed, wells at 378-379 

Fort Thompson, well at 348 

Fort White, section near 84 

spriags at 287 

wells at and near 287, 288 



Page. 
Fossils, occurrence of. See particular forma- 
tions. 

Francis, wells at 394 

Franklin County, description of 305 

geology of 305-306 

public water supply in 254, 306 

water supply of 306-308 

wells in, records of 305,306 

Freeport, public water supplies at 254 

wells at 424, 425 

water in, head of 237 

Fruitland Park, well near 342 

Fruitville, wells near 364 

Fuller's earth, deposition of 202 

occurrence and character of 108, 110, 112-115 

G. 

Gadsden County, description of 308 

geology of 308-310 

public water supplies in 254 

water supply of 310-312 

wells in, records of 309-310 

type of, view of 230 

Gainesville, public water supply at 254 

rock near 74, 75, 92, 143-144 

section near 144 

soil near 40 

springs at 266-267 

weUs at and near 266 

water of 226 

Geography, description of 21-64 

Geologic history, account of 66, 199-218 

Geologic map of Florida In pocket. 

Geology, record of 65 

rocks of, description of 71 

succession of 65-70 

table of 68-70 

See also particular counties. 

Georgiana, wells at 276 

Gidley, J. W., on Peace Creek bone beds. . . 142-143 

Glen, well near 294 

Glenwood, weUs at and near 418 

Goldsbor 0, wells at 378-379 

Gomez, geology near 381 

wells near 382, 384-385 

Gorrie, Dr., cited 213 

Goulding, wells at 304 

Graceville, wells at 329-330 

Grandin, wells at 394 

Grand Island, wells at 342,343 

wells at, records of 340-341 

Grand Ridge, wells at and near 329-330 

Grant, wells at 276 

Gravel, water-bearing quaUty of 242 

Gray sand, distribution and character of.. . 154-155 

Green Bay, wells at 390 

Green Cove Springs, public water supply at. . 254 

springs at 29,284-285 

wells near 284 

Green Spring, data on 323,324-325 

Greenville, wells near 360, 361 

Greenwood, weUs at 329-330 

Griffins Creek, rock at 94 

Griswold, L. S., work of 43, 178, 180 

Groimd water. See Water, underground. 

Gulf Hammock, spring at 356 

Gulf Stream, shore modifications by 63-64 

GuUiver, F. P., cited 38,39 



436 



IKDEX. 



Page. 

Gunter, Herman, work of 18 

Gj^sum, occui'rence of 76 

H. 

Hague, wells at 266 

Haile, wells at 266 

Hamilton Coimty, description of 312 

geology of 312-313 

springs of 314 

water supply of 313-315 

Hammock lands, fertility of, source of 40 

Hampton Springs, spriags at 414, 415 

wells near 271, 272, 414 

Hanson, wells at 312 

Hastings, wells at and near 396, 398 

records of 396 

Havana, public water supply at 254 

weUsat 310-312 

Hawthorn, rock near 89 

springs at 266,267 

wells at 266 

Hawthorn formation, character of 70 

87-89, 203, 246 

deposition of 203 

distribution of 90-93 

fossils of ; 89-90 

stratigraphic position of 88-89 

structure of 90 

water in 246, 249-250 

See also particular counties. 

Heilbron Springs 270, 272 

Heilprin, A., cited 79, 80 

82, 85, 102, 108, 116-117, 126, 134, 160 

Hernando, rock near 85 

wells near 281,282 

Hernando County, description of 316 

geology of 316-317 

springs of 317, 319 

water supply of 317-319 

Hemdon, well near 386-387 

Hickman, well at 294, 295 

Highland, wells at 285 

High Springs, rock near 84 

springs at 266, 267 

wells at 266 

HiU, R. T. , cited 207 

Hillsboro County, description of 319 

geology of 320-321 

public water supplies in 254, 323 

springs of 323 

water supply of 322-323 

weUs in, records of 320-321 

Hillsboro Inlet, geology at and near. . . 192, 196-197 

History, geologic, account of 66, 199-218 

Hobe Sound, wells at 382, 384-385 

wells at, water of, quality of 260 

Holder, wells near 281, 282 

HoUand, rocks near 115, 132, 133 

HollyhiU, weUs at 418 

Holmes County, description of 325 

geology of 325 

water supply of 326-327 

Homestead, wells at 292 

Homosassa, springs near 281, 282 

Hovey, E. O., on weU records 170-173, 181 

Hudson, wells at 387 

Hull, wells at 294-296 



Page. 

Human remains, occurrence of 162-163, 215 

Hunt, E . B . , cited 180, 183, 185, 187, 197 

Hunter, wells at 392 

Huntington, wells near 392 

Hurds, weUs at 396 

Hypoluxo, rocks near 176 

wellsnear 384-385 

record of. 383 

I. 

Indian Key, rocks of. 187 

Indian Key Channel, rocks at 187, 195 

weU at 168, 372 

record of 169 

Indianola, wells at 276, 277 

Inlets, occurrence and character of. 38 

Interlachen, wells at and near 392, 394 

weUs at and near, record of 392 

Inverness, wells near 281, 282 

Irrigation, practice of 41 

Island Grove, weUs at 266 

Istachatta, wells near 318-319 

J. 

Jackson County, description of 327 

geology of 327-328 

public water supplies in 254, 329 

water supply of 328-330 

Jacksons Blufl,rocks near 133 

section of 128 

Jacksonville, public water supply at 254 

rock near 125, 297 

section near 124-125 

wells at and near 300-301 

records of 298,299 

water of, head of 236 

J acksonville formation, character of 66, 

69,123-125,246 

distribution of 66, 126-127 

fossils of 125-126 

stratigraphic position of 123 

structure of 126 

water in 246, 251, 375 

See also particular counties. 

Jane Jay, wells at and near 390 

Jasper, wells at and near 313, 315 

Jefferson County, description of 330 

geology of 330-331 

public water supply in 254 

springs of 332,334 

water supply of 331-334 

Jensen, wells at 400 

Johnson, wells at 394 

Johnson, L. C, cited 80, 81, 163-164 

Josephi Island, well on, record of 348 

Judson, wells at and near 355, 356 

Juliette, spring near 367, 369 

wells at and near 367, 368 

Jupiter, well at, water of, assay of 260 

Jupiter Inlet, geology at 192, 197 

K. 

Kendrick, well at 367 

Kerr, W. C, and Mitchell, E., cited 102 

Keuka, wells at 394 



INDEX. 



437 



Page. 

ivc> Largo, location and character of 61 

Key Largo limestone, character of 68, 186-187 

distribution of 188-189 

fossils of 188 

stratigraphic position of 186 

synonymy of 184r-186 

view of 178, 184 

Keys, altitude of 61 

area of 42 

character of 44, 59-61, 187-188 

springs on 257 

wells on 169-173 

records of 169, 171-173 

See also Florida reef. 

Keys (p. — ), wells at 292 

Key Vaca, mangroves on, view of 63 

rocks on 187,189,195 

wells on 169-170,174 

record of 169 

Key West, location and character of 61 

rocks on 181,183,187,188 

springs on 371 

wells on 170-172, 174, 371-372 

records of 171, 172 

Key West oolite, analysis of 18* 

character of 68, 181-182, 184 

fossils of 182 

mud cracks in, view of 184 

origin of 182-184 

stratigraphic position of 180-181 

synonymy of 180 

view of 184 

King, F. H., cited 222 

Kingsford, wells at 390 

King Spring, occurrence and character of 356 

Kissimmee, rocks near 141, 152, 153, 158, 380 

salt water near 227 

wells at and near 254, 377, 380-381 

water in, head of 237, 380, 381 

Knights Key, beach of, view of 62 

well on 170, 372 

Knoxhill, rock near 101, 111, 121 

section near 121 

Krome, W. J., cited 55 

Kynesville, rocks near 79, 328 

L. 

Labelle, sections near 136,137 

Lacoochee, wells at. 387 

Lacustrine deposits, distribution and charac- 
ter of 159 

Ladylake, well near 342 

Lafayette County, description of 335 

geology of 335 

water supply of 335-337 

Lafayette formation, character of 66, 69, 147-148 

correlation of 146-147 

distribution of 148-150 

fossils of 148 

soils from 39-40 

springs from 228-229 

stratigraphic position of 147 

structure of 148 

view of 148 

water in 245,253 

quality of 253 

See also particular counties. 



Page. 

Lake Beresford, wells at and near 41 8 

Lake Bird, wells near 414 

Lake Charm, well at 378 

Lake City, public water supply at 254, 287 

rock near 92 

sections at and near 91,92 

wells at and near 287, 288, 409 

Lake County, description of 338 

geology of 338 

public water supply in 254 

springs of 342,343 

water supply of. 341-343 

wells in, records of. 339-341 

Lake Helen, wells at 418,419 

Lake Kerr, well near 367 

Lakeland, geology near 158 

public water supply at 254,390 

wells at 390 

Lake Mary, wells near 377-379 

Lake Ogden, wells at and near 287 

Lake Park, Ga., sink near, views of 27 

Lake region. See Upland region. 

Lakes, nature of 24-25,30 

Lakeview, wells at 426 

Lakewood, wells at 424,425 

Lake Worth, rock near 74 

Lamont, springs near 334 

wells at 331-333 

Land-pebble phosphate. See Bone Valley 
gravel. 

Langdon, D., cited 71,86,87 

Lanier, well near 380 

Lantana, dunes near 48 

Lapenotieres Spring, section near 107 

Laurel Hill, wells at and near 425, 426 

Lawtey, wells at 272 

Lebanon, spring near 356 

wells near 355 

Lecanto, wells near 281, 282 

Lee, wells at and near 360,361 

Lee Coimty, description of. 344 

geology of 344 

springs in 345 

water supply of. 344-350 

wells in 345-350 

flows from 258,259,345,350 

records of. 346-349 

water of, assays of 260 

quality of 260 

Leesburg, public water supply at 254, 342 

wells at 342, 343 

Leon County, description of 350 

geology of 350-351 

public water supply in 254, 352 

water supply of 351-353 

Leroy, wells near 367 

Levy County, description of 354 

geology of 354 

springs of 356 

water supply of 354-356 

Levyville, rock near 91 

spring near 355 

wells near 355,356 

Levyville formation , correlation of 70, 80 

Lewis, E., cited 214 

Liberty County , description of 357 

geology of 357-358 

water supply of 358 



438 



INDEX. 



Lime, use of, as fertilizer 41 

Limestone, solution and transportation of. 26, 52, 161 

water-bearing quality of 243 

Linton, rock near , 178 

Literature, list of 17-19 

Live Oak, public water supply at 254, 409 

rock near 91 

well near, water of 226 

wells at and near 410,412 

Liverpool, well at 294,295 

Lloyd, wells near 333 

Loam soils, distribution and character of 41 

Loess, geologic relations of 210-211 

Longboat Key, well on 364 

Long Key, geology of 180,183,197 

Longwood, wells at 378-379 

Lostmans Key, wells on 371 

Lostmans River, rocks on 190, 191 

Lostmans River limestone, character of 68, 190 

distribution of 190-191 

origin of 191 

stratigraphic position of 189-190 

synonymy of 189 

Lotus, wells at 276 

Loughman, wells at 389,390 

Lower Metacumbe, sands at 197 

Lowland, description of 30-35 

Luraville, rocks near 408 

wells near 409-412 

Luther, wells near 414 



M. 



McAlpin, wells at and ne^: 411 

Maccleny, wells of 268-269 

Mcintosh, weUs near 367 

Madison, public water supply at 254 

wells at and near 360, 361 

Madison County, description of. 359 

geology of , 359 

public water supply in 254 

springs of 360-361 

water supply of 359-361 

Magnesia spring, occurrence and character of. . 267 

Magnesia Springs, rock near 91 

Magnolia Springs, sprtags at 285 

wells near 284 

Mainland, altitude of 21-23, 45 

subdivisions of 25, 45 

See also Upland region; Lowland; Coast; 
Pinelands; Swamps. 

Maitland, wells at and near 378-379 

Malabar, wells at 276 

Manatee, wells at and near 364 

wells at and near, water in, head of. 237 

Manatee County, description of 362 

geology of 362-363 

public water supply ia 254, 364 

water supply of 363-364 

wells in, records of 363 

Mandarin, wells at and near ^ — 300 

Mangroves, distribution and character of 59, 60 

view of 63 

Manhattan Beach, wells at 300 

Map, geologic and topographic In pocket. 

B, wells near 281 



Marathon, wells at 169-170, 372 

wells at, record of 169 

water of, assays of 260 

Marco, rocks near 190 

wells near 348 

record of 346 

water of, assay of 260 

Marianna, public water supply at 254, 329 

rock at and near 72, 77-78 

sections at and near 77 

wells at and near 329-330 

Marianna limestone, character of 70, 73-74, 247 

correlation of 73 

distribution of 75-79 

fossils of 73,74 

stratigraphic position of 73 

structure of 74-75 

water in 247,279,304,326,329 

Marine deposits, water of, sweetening of 207- 

208,225-226 

Marion, well at 315 

Marion County, description of 365 

geology of 365-366 

public water supplies in 254, 367 

springs of 366-367, 369 

water supply of 366-369 

wells in, records of 365-366 

Marls, distribution and character of 151-154, 

194, 196, 197, 198 

origmof 196,216 

soils from 40 

See also Planorbis; Chipola; Shoal River; 
Choctawhatchee; Caloosahatchee; 
Nashua; and Shell marls. 

Martel, wells at and near 367, 368 

Martin, well near 367 

Matanzas, well near 396 

Matson, G. C, county descriptions by 263-288, 

294-343, 350-369, 373-381, 385-430 
on geography of northern and central 

Florida 21-42 

on geology of northern and central 

Florida 65-166 

on underground waters 219-254 

work of 18, 19 

Matson, G. C, and Sanford, S., on geologic 

history 199-218 

Maury, C. J., cited 76, 96 

Maxville, wells near 284, 300 

Mayo, public water supply at 254 

wells at and near 337 

Mayport, wells at and near 300, 301 

wells at and near, record of 298 

Maytown, well at 378 

Medulla, wells at 390 

Melbourne, rocks near 85 

springs near 277 

wells near : 276, 277 

record of 274, 275 

Melrose, springs at 266, 267 

wells at 266 

Merritts Island, rocks of 273 

wells on 276 

Miami, fossils near 179 

rock near 178,179,180,183 

springs near 289 



IKDEX. 



439 



Page. 

Miami, wells at and near 291-293 

wells at and near, records of. 291 

water of, assay of 260 

Miami oolite, character of 68, 178-179, 216, 257 

distribution of 180 

fossils of 179-180 

springs from 256 

stratigraphic position 178 

synonymy of 177-178 

view of 178 

water in 289 

Micanopy, well at 266 

well at, record of 264 

Micco, wells near 276 

Middleburg, section near 126-127 

springs near 284 

wells near 284 

Mikesville, wells at. 287 

Miliolite limestone, correlation of 85 

Mill Creek, rocks on 133 

Milligan, rocks near 401 

Millview, public water supply at 254 

wells at 304 

Millville, wells at 428,429,430 

Milton, wells at and near 402-403 

Mimms, geology at 273 

wells at 277 

Mineralization of undergrouBd water, causes 

of 225-227,261,262 

See also Water, imdergroimd. 

Miocene series, deposition of 204-205 

formations of 66, 69, 122-123, 246 

occurrence and character of 123-133, 

167, 168, 170, 171, 173-174, 204r-205, 246 

nomenclature of 121-123 

water in 246,251-252,258 

See also particular counties. 

Miocene time, events in 203-205 

Mitchell, E ., and Kerr, W. C, cited 102 

Mixons, rock near 91 

Molino, wells at 304 

Monroe, wells near 377, 378 

Monroe County, description of 370 

geology of 370 

springs of. 371 

water supply of. 370-372 

wells in, water of, assays of 260 

Montague, wells near 367 

Monthook, wells at 355, 356 

Monticello, public water supply at 254 

weUsat 331-333 

Morriston, wells at 355, 356 

Mound, ancient, view of 154 

Mount Dora, wells at and near 342, 343 

wells at and near, record of 340 

Muck soils, distribution and character of 39 

use of 41-42 

Mulat, wells at 304 

Mulberry, public water supply at 254 

wells at and near 389, 390 

Muscogee, wells at and near 304 

N. 

Naranja, wells at 292 

Nturcoossee, wells at and near 380, 381 

Nashua, rocks near 133, 140 

rocks near, view of 140 



Nashua marl, character of 66, 69, 139 

contact of, view of 140 

discrimination of 138 

distribution of 140-141 

fossils of 139-140 

stratigraphic position of 139 

structure of. 140 

water in 245, 252 

See also particular counties. 

Nassau County, description of 373 

geology of 373-374 

public water supplies in 254 

springs of 374 

water supply of 374-376 

wells in, records of 374 

Natural Bridge, rock near 78-79, 423 

Natural bridges, occurrence and character of. 28-29 

Newberry, rock near 84 

wells at 266 

Newberry terrace, description of 32-33 

Newbridge, view at 94 

Newbum, well near 411 

Newfound Harbor, rocks at 188 

Newland Spring, occurrence and character of. 29, 

409,412 

Newnansville, rock near 91 

Newport, springs near 422 

New Smyrna, wells at and near 418 

view of 230 

Nichols, wells at 324,389,390 

Nigger Sink, rock at 90-91 

Nocatee, wells at and near 294, 295 

North Indian River, mound in, view of 154 

Northrop, wells at and near 304 

Norwalk, springs near 369 

Nummulitic limestone, correlation of — .... 70, 80 

O. 

Oak, wells near 367 

Oak Grove sand member, distribution and 

character of 119-120 

fossils of 119 

Oak Hill, weUs near 418,419 

water of, quaUty of 276 

Oakland, wells at and near 378 

O'Brien, wells at and near 411,412 

Ocala, fossils from 143 

pubhc water supply at 254,367 

quarry near, views in 80 

rock at and near 83, 365-366 

section at 83 

spring near 366-367,369 

wells at and near 367-368 

record of 365-366 

Ocala limestone, character of 70, 81-82, 247 

distribution of ':.... 82-85,286 

fossils of 82 

nomenclature of 79-80 

stratigraphic position of 80-81 

structure of 82 

views of 80 

water in 247, 406 

Ocean currents, work of 38-39, 63-64 

Ochlockonee River, section on 128 

Ocheesee beds, correlation of 70, 93 

Oclakatchee Lake, sink of, view of 27 

Ocoee, wells at 378-379 



440 



INDEX. 



Page. 

Odessa, well near 386-387 

Okahumpka, spring near 342, 343 

wells near 342, 343 

Okaloacoochee Slough, cypress in 58 

Okechobee, Lake, drainage of 54-55 

soils near 39 

See also Everglades. 

Old Miocene, correlation of 69, 71 

Oligocene series, deposition of 199-203 

formations of 66-67, 69-70, 71, 246-247 

occurrence and character of 71-121, 

167,173,246-247 

soils from 39 

waterin 246-251,256,258 

See also particular counties. 

Oligocene time, events in 199-203 

Olustee, wells of 269 

Oneco, wells near 364 

Oolite, analysis of 184 

formation of 162, 180, 181-184 

Orange City, public water supply at 254, 419 

section at 153 

wells at 418, 419, 420 

Orange County, description of 376 

geology of 376-377 

public- water supplies in 254 

springs of 378 

water supply of 377-379 

Orange Park, wells near 284, 285 

Orange Springs, springs near 367, 369 

weUs at 308 

Orchid, wells near 276 

Organic life, land building by 216-217 

Orient, section at 153 

Orlando, public water supply at 254 

sink near 376 

wells at and near 376, 378-379 

Ormond, geology near 153, 399, 416 

wells near 418 

record of 417, 418 

Orthaulax bed, correlation of 70, 102 

Osborne, Lake, depth of 49 

sand dunes near 48 

Osceola, wells at.. 266 

Osceola County, description of 379 

geology of 379-380 

water supply of 380-381 

Osprey, human remains near 162-163 

sections near 163 

well near 364 

Otter Creek, spring near 355, 356 

wells at and near 355, 356 

O viedo, wells at 378-379 

Oxford, wells at and near 406-407 

wells at and near, records of 40 

Oyster reefs, occurrence and character of... 160, 198 



Pablo Beach, public water supply at 254, 300 

wells at 300,301 

Padget, well at 392 

Palatka, public water supply at 254, 393 

wells at 392-394 

records of 392 

Palm Beach, geology near 154, 

176,176,192,195,196-197 



Palm Beach, sand dunes neat 48 

wells at and near 168, 382, 384-385 

records of 168, 383 

Palm Beach County, description of 381 

geology of 381-382 

springs in 382 

water supply of 38^-385 

wells in, flows from 258,384 

records of 382-384 

water of, assays of 260 

Palm Beach limestone, character of 68, 176 

distribution of 177 

fossils of 176 

stratigraphic position of 176 

structure of 177 

synonomy of 175-176 

Palmer, wells at 266 

Palmetto, wells at and near 364 

Panacea, spring near 422 

Panasoflfkee, wells at 407 

Panther Key, wells on 371 

Parish, wells at and near 364 

Park, well at 378 

Pasadena, well near 386-387 

Pasco, well near 386-387 

Pasco County, description of 385 

geology of 385-386 

water supply of 386-387 

Pavilion Key, wells on 371 

Peace Creek, rocks on 146 

sections on 138 

Peace Creek bone bed, correlation of. 69, 138, 141-143 

fossHsof 142-143 

Peat, distribution and character of. 195-196, 198-199 

relations of 58 

soUs from, distribution and character of.. 39 

use of 41-42 

Pebbledale, wells at 390 

Pebble phosphates. See Bone Valley gravel. 
Peck Mineral Springs, occurrence and charac- 
ter of 285 

Peniel, wells at 392,394 

Peninsular limestone, character of 70, 73-74, 247 

distribution of 75-79 

fossils of 73 

stratigraphic position of 73 

structure of 74-75 

water in 247, 

269, 272, 277, 296, 301, 324, 364, 378, 381, 390 

Pensacola, public water supply at 254 

rocks at " 75 

wells at and near 304 

record of 303 

Pensacola terrace, description of 34-35 

Perched water table, figure showing 225 

nature of 225 

Perrine, wells at 292 

Perry, springs at 414, 415 

wells at and near 414, 415 

public water supply at 254, 414 

Phosphate rock, iavestigattion of 18 

occurrence of 76,90-91 

Phosphoria, wells at 390 

Picolata, well near 396 

Pierce, wells at 390 

Pierce, James, on coquina 155-156 



INDEX. 



441 



Page. 

Pierson, wellnear 418 

Pine Barren, wells at 304 

Pine Island, sand dunes on 48 

Pinelands, area and distribution of 45-46 

character of 46-52 

See also Sand dunes; Sand plains; Flat- 
lands; Ridges. 

Piuella County, organization of 387 

See also Hillsboro County. 

Piaemount, wells at and near 411, 412 

Ptaetta, springs near 360 

wells at and near 360, 361 

Planorbis marl, distribution and character 

of 155,175 

Plant City, public water supply at 254 

wells at and near 322,324 

record of 320-321 

water of 226, 323, 324 

Plants, evaporation through 223 

Plantation Key, rocks of 189 

Pleistocene series, expression of 158 

formations of 68, 151, 174-175, 245 

correlation of 191-192 

description of 175-191 

fossils of 151-154,158 

nthologyof 192-195 

marls of 151-154, 194 

soil from 40 

sand of 154-157,193 

contact of, view of 140 

soil from 39 

stratigraphic position of 156-157 

structure of 158 

thickness of 157-158, 194-195 

water in 245, 253-254, 258 

See also particular counties. 

Pleistocene terraces, formation of 210-211 

location of, map showing In pocket. 

occurrence and character of 31-35 

Pleistocene time, events ta 207-212 

Pliocene series, deposition of 206-207 

formations of 66, 69, 13, 147, 245 

occurrence and character of 134-150, 

167,171,173-174 

soils from 39 

water in 245,252-253,258 

See also particular counties. 

Pliocene time, events in 205-207 

Plummer, wells at 300 

Poe Spring, occurrence and character of 29, 267 

Polk County, description of 388 

geology of 388-389 

pubUc water supplies in 254 

water supply of 389-390 

wells ta, records of 389 

Ponce de Leon, wells at 326-327 

Ponce Park, wells at and near 418, 419 

Ponds, occurrence and character of 31 

See also Lakes. 

Port Orange, wells at and near 418 

Port Richey, weU near 386-387 

Port Tampa, wells at 324 

Potable water, depth to 225-227 

thickness of sediments containing 222 

Potholes, formation of 187 



Page. 
Profile section across Florida, figure showing. 225 

Providence, weUs near 270, 271 

Public water supplies, table of 254 

Pumpelly, R., cited 93-94 

Pumping, effect of, on artesian head 239, 241 

water wheel for, view of 234 

Punta Gorda, wells at and near 294, 296 

Punta Rasa, wells at and near 348 

wells at and near, records of 347 

water of, assays of 260 

Putnam County, description of 391 

geology of 391-392 

public water supplies in 254, 393 

springs of 393 

water supply of 392-394 

wells in, records of 392 

Putnam HaU, wells at 394 



Quaternary system, formations of, descrip- 
tions of 151-163,245 

subdivisions of 150-151 

water in 245, 254 

Quincy, fuUer's earth near 113-114 

public water supply at 254 

rock at 74, 95 

section near : 113 

wells at and near 310-312 

record of 309-310 

view of 230 

water of 226 

R. 

Rabbit Key, rock on 198 

Rainfall, disposition of 220, 255 

effect of, on artesian head ....'. 238-239 

records of 219-220 

Rams, hydraulic, use of 233 

Recent series, formations of 68, 158, 195, 216, 245 

formations of, description of. . . 159-163, 195-199 

water in 245, 254 

Recent time, events in. 212-218 

Redbay, rocks near 129, 130 

Reddick, wells at 368 

Red Oak, weUs near 360 

Reefs, coral, occurrence and character of 35, 

42,61-62,160,197-198 

view of 62 

Reefs, oyster, occurrence and character of 160 

Relief, character of 21-23,43-44 

map showing In pocket. 

description of 21-22 

Rice Creek, weUs at 392 

Richland, weU near 386-387 

Ridges, rock, erosion of 51-52 

occurrence and character of 31, 51-52, 165 

River Junction, fossils near 101 

rocks at and near 100 

sections at and near 100-101, 112, 150 

wells at 3 12 

Rivers. See Streams. 

Riverside, public water supply at 254, 300 

Robinson Point, weUs on 403 

Rochelle, wells at 266 



442 



INDEX. 



Page. 

Rock, outcrops of 31, 51-52, 55-57, 60 

underground solution of. See Drainage, 
underground. 

Rock Blufl, rocks near 110, 112-113 

section at 113 

Rock Hill, rocks on, view of 148 

Rockledge, wells near 276 

Rock Springs, rock near 127 

wells at and near 367,368 

Rodman, Wells at 392 

Rose, R. E., cited 57 

Roseland, wells near 276 

Rossburg, well at 411 

Run-off, proportions of 220 

Runways, tidal, occurrence and character of. 38 

Rural, well at 318 

Russell, wells near 284 

S. 

Safety Harbor, rocks near 106 

section near 106 

springs near 324-325 

St. Augustine, public water supplies at 254 

rocks at 74,127,395 

submarine spring near 207-208, 213, 236 

wells at and near 396 

record of 395, 396 

view of 32 

water in, head of 236 

St. Francis, well near 342 

St.- James, wells at 348 

wells at, water of, assays of 260 

St. John County, description of 394-395 

geology of 395 

public water supplies in 254 

springs of 397 

water supply of 396-398 

wells in, records of 395-396 

St. Johns River, rocks on 138-141, 152, 159 

St. Leo, well near 386-387 

St. Lucie County, description of 398 

geology of 398-399 

water supply of 399-400 

wells in, records of 399 

St. Marks, rock near .' 101 

uplift near 214 

St. Marys River, terrace on, view of 32 

St. Nicholas, wells at 300, 301, 421 

St. Petersburg, public water supply at 254, 323 

wells at 322,323,324 

water in, head of 236, 323, 324 

Salt water, underground, comparison of sea 

water and 262 

distribution of 226-227, 259, 260 

relation of, to fresh water 261-262 

- to uplift 226, 262 

drainage of, from rocks 207-208, 225-226, 262 

San Antonio, wells near 386-387 

Sand, color of 46-47,50,193 

distribution and character of. . 193, 196-197, 198 

water-bearing quality of 242 

Sand dunes, distribution of 47-49 

occurrence and character of. 30, 3 1, 46-47, 160-161 

quiescence of 47 

Sanderson, wells of 269 

Key,rocks of 188 



Page. 
Sand plains, distribution and character of. . . 49-50 
Sanford, public water supply at 254, 378 

wells at 377-379 

water in, head of 237 

Sanford, Samuel, cited 24 

county descriptions by 288-293, 

344-350, 370-372, 381-385 

work of 19 

on geography of southern Florida 42-64 

on geology of southern Florida 167-199 

on waters of southern Florida 255-262 

Sanford, S., and Matson, G. C, on geologic 

history 199-218 

Sanibel Island, wells on 348 

wells on, record of 347 

water of, assay of 260 

San Mateo, wells at and near 392, 394 

Santa Fe River, natural bridge on 28 

sink of, view of 27 

Santa Rosa County, description of 401 

geology of 77,401-402 

water supply of. 402-403 

Sarasota, wells near 364 

Sarasota Key, rock on 192 

rock on, view of 154 

Seabreeze, wells at 418 

wells at, water in, head of 236, 418 

Sea water, comparison of, to underground salt 

water 262 

Seepage, recovery of water by 228 

water from, quality of 228 

Sellards, E . H., cited 26, 85, 89, 376 

work of. 18,224,249 

Seminole Spring, occurrence and character 

of 342,343 

Senterflt Creek, deposits on 120 

Seville, public water supply at 254, 419 

wells at and near 392 

Shaler, U. S., cited 164, 177-178, 207-208 

Shark River, rock on 190, 196 

Shark River Archipelago, character of 59 

Sharpes, wells at and near 276 

wells at and near, water of, quality of . . . . 276 

Shattuck, G. B., cited 211 

Shell Bluff, section at 120 

Shell marl, water-bearing quality of 243 

Shoal River marl member, distribution and 

character of 120-121 

fossils of 120-121 

Shore liae. See Coast. 

Silex bed, correlation of 70, 102-104 

deposition of 203 

See also Tampa formation. 
Silver Spring, spring near 29,369 

wells at and near 367, 368 

Sinlcs, absorption of rain by 220 

location of, in Williston quadrangle, map 

showing 26 

occurrence and character of 26-28, 30, 52, 56 

views of 26,27 

See also particular counties. 

Sirmans, wells at and near 360, 361 

Smith, B ., cited 177 

Smith, E . A. , cited 75-76 

Sneads, wells at and near 



INDEX. 



443 



Page. 
Soils, distribution and character of... 39-40,198-199 

evaporation from 222-223 

origin of 39-40 

types of 40-42 

Solution, underground, progress of 26, 52 

Sombrero Key, sands at 198 

Sopcboppy limestone, character of 118 

correlation of 69, 108 

water in 306 

Sorrento, spring near 342,343 

wells near 342,343 

Sounds, occurrence and character of 37 

ship passage through 37 

Southwest Cape, formation of 39 

South Jacksonville, public water supply at. 254, 300 

wells at and near 300,301 

Southport, wells at 429 

Sparr, wells at and near 367,368 

Spears Grove, wells at 378-379 

Spouting Rocks, geology at 192, 193 

Spring Park, wells near 368 

Springs, occurrence and character of 29, 

228-229,256-258 

relation of, to water table 224-225 

figures showing 224, 225 

water of, quality of 229 

Springs, submarine, occurrence and character 

of 207-208, 213, 236, 256-257 

Stanley-Brown, -J., and Dall, W. H., 

cited 112-113,129 

Starke, springs at and near 270, 272, 285 

wells at and near. 270, 271 

State Reform School,public water supply at. 254, 329 

Stetson, wells at 418, 419 

Streams, character of 23-25, 30, 31 

sinks of 27 

Structure of northern and central Florida. . 163-166 

of southern Florida 199 

Stuarts Bridge, rock near 116 

Submergence, effect of possible 44 

occurrence of 202, 

204, 205, 209-210, 211, 212-213, 215 

Subtropical Miocene, correlation of 69, 71 

Sulphur, deposition of 161 

Sumter County, description of 404 

geology of 404-405 

springs of 406 

water supply of 406-407 

Sumterville, springs near 406 

wells at and near 208, 406, 407 

Suwannee, spring near 29, 409, 412 

weUsat 412 

Suwannee Cpunty , description of 408 

geology of 408 

pubUe water supply in 254, 409 

springs of 409, 412 

water supply of 408-412 

Swamps, controUing conditions of 45, 52-53 

distribution and character of 25, 52 

iSceaZso Everglades; Coastal swamps; Cy- 
press swamps. 
Switzerland, weUs near 396 



5, fuUer's earth near 114-115 

pubhc water supply at 254 

sections near 114, 149 

wells at and near ....... 352, 353 



Page. 

Tampa, public water supply at 254, 323 

rocks at and near 75, 76, 95-96, 102, 105-107 

sections at 105, 106 

springs at 323, 324-325 

wells at and near 322, 323, 324 

water in, head of 237, 238, 323, 324 

Tampa formation, character of 70, 102-104, 246 

distribution of 105-107 

fossils of 104-105 

nomenclature of 102-103 

soil from 40 

stratigraphic position of 103 

structure of 105 

view of 94 

water in 246, 250 

See also particular counties. 

Tarpon Springs, pubUc water supply at 254, 323 

rock near 84 

spring at 29 

wells at 322,323 

Tavares, weUs at and near 342, 343 

Taylor County, description of 413 

geology 413 

public water supply in 254 

springs of 414,415 

water supply of 413-415 

Ten Thousand Islands, character of 59, 60 

rocks of 189, 196 

Terra Ceia Island, weUs on 364 

record of 363 

Terraces, character of 31-35 

occurrence of 31-35 

map showing In pocket. 

Terrell, well near 318 

Tertiary system, description of 71-150, 245-247 

functions of 69-70 

water in 245, 254 

Thomas City, spring near 332,334 

Thonotosassa, weU near 323, 324 

Tibbals, wells at 400 

Tides, effect of, on artesian head 237-238, 256 

land building by 217 

runways for, occurrence and character of. 38 

Tiger Bay, wells near 390 

Tildenville, wells at 378 

Titusville, rocks near 153, 273 

wells at and near 276, 277 

water of 227, 276-277 

Topographic provinces, features of 25 

See also Upland; Lowland; Coast. 

Topography, character of 21-23, 43-44 

relation of, to water table 224-225 

figure showing 224 

See also Mainland; Keys; Coast; Drain- 
age; Relief. 

Traders Hill, Ga., terrace near, view of 32 

Traxler, springs at 266, 267 

wells at 266 

Trilby, well near 386-387 

Tropic, wells near 276 

Tsala Apopka terrace, description of 33-34 

Tuomey, M., cited 94, 177, 180, 185 

Turtle Mound, view of 154 

Tyler, wells at 266 

U. 

Umatilla, wells at 343 

Undergroimd water. See Water, under- 
ground. 



444 



INDEX. 



Page. 

Union Spring, oecurrGnce and character of. . . 415 

Upland region, position of 22-23 

springs of 29 

surface features of 28-30 

underground drainage of 25-28 

Uplift, estimates of 207-209 

occurrence of 201- 

202, 203-204, 207-209, 211, 212, 214-215 

Useppa Island, wells near 348 

V. 

Valkaria, wells near 276 

Vaughan, T. W., cited 19, 

78, 149, 161-162, 168, 181, 183 

fossils determined by 95-96 

126, 130, 132, 133, 153-154, 179-180, 182, 416, 418 

on deposition of rocks 200-201 

on Alum Bluff formation 111-116, 119-121 

on Cliattahoochie formation 95-98 

on geologic history 200, 

203, 205, 206-207, 209-210, 214 

on human remains 162-163 

on Miocene 126, 127, 128, 130, 132, 133 

on ocean currents 63-64 

work of 17, 19 

Vermetus rock, distribution and charac- 
ter of 156, 160 

Vernon, public water supply at 254 

rocks near 130 

sink near, view of 26 

wells at 429,430 

Vicksburg, Miss., rocks at 73 

Vicksburg group, deposition of 199-201 

formations of 67, 70, 72-73, 247 

description of 73-85, 247 

nomenclature of 71-73 

soil from 40 

springs from 29, 229 

water in 67, 234, 235, 247-249, 250-251, 258 

quaUty of 280 

See also particular counties. 

Volusia County, description of 416 

geology of 416-418 

public water supplies in 254, 419 

springs of 419, 420 

water supply of 418-420 

wells in, records of 417 

Wacahoota, wells at 266 

Wacissa, spring near 332,334 

Wades, wells at 266 

Wakulla Coxmty, description of 420 

geology of 420-421 

springs of 422 

water supply of 421-422 

Wakulla Spring, occurrence and character of. 422 

Waldo, wells at 266 

V/aldo formation, correlation of 70 

Waldo Spring, occurrence and character of. . . 415 
Walker Spring, occurrence and character of. 332, 334 

Walkill, wells near 284 

Walton County, description of 422 

geology of 77, 78, 101, 423 

public water supplies in 254 

springs of 425 

water supply of 424-426 

wells in, record of 423 



Washington Coimty, description of 426 

geology of 426-427 

public water supplies in 254 

sink in, view of 26 

water supply of 428-430 

wells in, records of 427 

Water, underground, amount of 221-222 

assays of 260 

circulation of 227-228, 261-262 

depth to 224-227, 255-256 

evaporation of 222-223 

mineralization of 225-227, 261-262 

occurrence of, in rocks 242-254 

pollution of, danger of 229-231, 258 

potable supplies of, depth to 225-227, 261 

quality of 225-227, 243, 244, 249-254, 259-262 

recovery of 228-234 

source of 219-220, 255 

See also Water table; Artesian water; Water- 
bearing materials; Springs; Wells; Salt 
water; particular counties. 

Water-bearing materials, character of 242-243 

formations of, conditions governing 243-247 

description of 248-254, 258 

Water supplies, public, table of 254 

Water table, depth to 255 

nature of 224-225 

relation of, to springs and surface con- 
tour 224-225 

figures showing 224, 225 

Watertown, wells at 288 

Water way, through sounds, plan for 37 

Waterv/heel, view of 234 

Wauchula, wells at and near 294-296 

Waukeenah, wells near 333 

Wausau, rocks at and near 427, 430 

Webster, wells at and near 406, 407 

Weekewachee Spring, occurrence and charac- 
ter of . 29, 317, 319 

Weirsdale, well near 367 

Wekiva Spring, description of 29, 355, 356 

view at 234 

Welaka, wells at 392,394 

Welborn, wells at and near 411, 412 

Wells, depth of, considerations governing. . 229-230 

making of 231-233 

multiplication of, effect of, on head 239-241 

placing of 230 

figures showing 230 

pumping from 233-234 

types of 229-230 

views of 32, 230 

water of, assays of _. 260 

source of 255 

See also particular places; Flowing wells; 
Dug wells; Bored wells; etc. 

West Jupiter, wells near 384-385 

records of 382 

West Palm Beach, dimes near 48 

See also Palm Beach. 

West Sopchoppy, deposits at and near 115 

West Tampa, public water supply at 254, 323 

wells at 322,323,324 

West Tocoi, wells near 284 

Westville, wells at 326-327 

White City, weUs near 276, 400 

White City Junction, wells near 400 



INDEX. 



445 



Whitehouse, wells near 300 

White Springs, rock at 91-92, 116, 118 

section at 91, 93, 115-116 

springs at 314 

wells at and near 315 

Whitewater Bay, character of 59, 60 

Whitfield, wells at 426 

Whitney, well near 342 

Whitney, Milton, on Florida soils 40 

Wilcox, wells at 268 

Wildwood, wells at 407 

WUeys Landing, section of 98 

WiUcox, J., cited 80, 82 

WiUeford, wells at 266 

Williams Crossing, well at 284 

Winis, Bailey, cited 189, 191 

Williston, wells at 355,356 

Williston quadrangle, sink holes in, map 

showing 26 

Willoughby, H. L., cited 55 

Windleys Island, rocks on 189 



Page. 
Windsor, wells at 266 

Winfield, wells at and near 287, 288 

Winter Garden, wells at and near 378-379 

Winter Haven, wells at and near 390 

Winter Park, wells at 378-379 

Woodbin-n, wells at and near 392, 394 

Worm rock, distribution and character of 198 

Worthington, public water supply at 254 

springs at 270, 272 

Y. 

Ybor City, wells at and near 322 

Yellow clay, distribution and character of . . . 156 

Yellow River, deposits on 119-120 

section at :... 119 

Yon, well near 328 

York, well near 387 

Z. 

Zolfo, wells at 29-1-296 

Zuber, well near 367 



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